Advanced Mediterranean Diet

At my Diabetic Mediterranean Diet blog, I recently noted that regular physical activity prevented or postponed death.  Onward now to other benefits.

Waist Management

Where does the fat go when you lose weight dieting?  Chemical reactions convert it to energy, water, and carbon dioxide, which weigh less than the fat.  Most of your energy supply is used to fuel basic life-maintaining physiologic processes at rest, referred to as resting or basal metabolism.  Basal metabolic rate (BMR) is expressed as calories per kilogram of body weight per hour.

The major determinants of BMR are age, sex, and the body’s relative proportions of muscle and fat.  Heredity plays a lesser role.  Energy not used for basal metabolism is either stored as fat or converted by the muscles to physical activity.  Most of us use about 70 percent of our energy supply for basal metabolism and 30 percent for physical activity.  Those who exercise regularly and vigorously may expend 40–60 percent of their calorie intake doing physical activity.  Excess energy not used in resting metabolism or physical activity is stored as fat.

Insulin, remember, is the main hormone converting that excess energy into fat; and carbohydrates are the major cause of insulin release by the pancreas.

To some extent, overweight and obesity result from an imbalance between energy intake (food) and expenditure (exercise and basal metabolism).  Excessive carbohydrate consumption in particular drives the imbalance towards overweight, via insulin’s fat-storing properties.

In terms of losing weight, the most important metabolic effect of exercise is that it turns fat into weightless energy.  We see that weekly on TV’s “Biggest Loser” show; participants exercise a huge amount.  Please be aware that conditions set up for the show are totally unrealistic for the vast majority of people.

Physical activity alone as a weight-loss method isn’t very effective.  But there are several other reasons to recommend exercise to those wishing to lose weight.  Exercise counteracts the decrease in basal metabolic rate seen with calorie-restricted diets.  In some folks, exercise temporarily reduces appetite (but others note the opposite effect).  While caloric restriction during dieting can diminish your sense of energy and vitality, exercise typically does the opposite.  Many dieters, especially those on low-calorie poorly designed diets, lose lean tissue (such as muscle and water) in addition to fat.  This isn’t desirable over the long run.  Exercise counteracts the tendency to lose muscle mass while nevertheless modestly facilitating fat loss.

How much does exercise contribute to most successful weight-loss efforts?  Only about 10 percent on average. The other 90 percent is from food restriction.

Fountain of Youth

Regular exercise is a demonstrable “fountain of youth.”  Peak aerobic power (or fitness) naturally diminishes by 50 percent between young adulthood and age 65.  In other words, as age advances even a light physical task becomes fatiguing if it is sustained over time.  By the age of 75 or 80, many of us depend on others for help with the ordinary tasks of daily living, such as housecleaning and grocery shopping.  Regular exercise increases fitness (aerobic power) by 15–20 percent in middle-aged and older men and women, the equivalent of a 10–20 year reduction in biological age!  This prolongation of self-sufficiency improves quality of life.

Heart Health

Exercise helps control multiple cardiac (heart attack) risk factors: obesity, high cholesterol, elevated blood pressure, high triglycerides, and diabetes.  Regular aerobic activity tends to lower LDL cholesterol, the “bad cholesterol.”  Jogging 10 or 12 miles per week, or the equivalent amount of other exercise, increases HDL cholesterol (“good cholesterol”) substantially.  Exercise increases heart muscle efficiency and blood flow to the heart.  For the person who has already had a heart attack, regular physical activity decreases the incidence of fatal recurrence by 20–30 percent and adds an extra two or three years of life, on average.

Effect on Diabetes

Eighty-five percent of type 2 diabetics are overweight or obese.  It’s not just a random association.  Obesity contributes heavily to most cases of type 2 diabetes, particularly in those predisposed by heredity.  Insulin is the key that allows bloodstream sugar (glucose) into cells for utilization as energy, thus keeping blood sugar from reaching dangerously high levels.  Overweight bodies produce plenty of insulin, often more than average.  The problem in overweight diabetics is that the cells are no longer sensitive to insulin’s effect.  Weight loss and exercise independently return insulin sensitivity towards normal.  Many diabetics can improve their condition through sensible exercise and weight management.

Miscellaneous Benefits

In case you need more reasons to start or keep exercising, consider the following additional benefits: 1) enhanced immune function, 2) stronger bones, 3) preservation and improvement of flexibility, 4) lower blood pressure by 8–10 points, 5) diminished premenstrual bloating, breast tenderness, and mood changes, 6) reduced incidence of dementia, 7) less trouble with constipation, 7) better ability to handle stress, less trouble with insomnia, 9) improved self-esteem, 10) enhanced sense of well-being, with less anxiety and depression, 11) higher perceived level of energy, and 12) prevention of weight regain.

People who lose fat weight but regain it cite lack of exercise as one explanation.  One scientific study by S. Kayman and associates looked at people who dropped 20 percent or more of their total weight, and the role of exercise in maintaining that loss.  Two years after the initial weight loss, 90 percent of the successful loss-maintainers reported exercising regularly.  Of those who regained their weight, only 34 percent were exercising.

Stay tuned for my specific exercise recommendations.

Steve Parker, M.D.

Swedish researchers reported recently that a Paleolithic diet was more satiating than a Mediterranean-style diet, when compared on a calorie-for-calorie basis in heart patients.  Both groups of study subjects reported equal degrees of satiety, but the paleo dieters ended up eating 24% fewer calories over the 12-week study.

The main differences in the diets were that the paleo dieters had much lower consumption of cereals (grains) and dairy products, and more fruit and nuts.  The paleos derived 40% of total calories from carbohydrate compared to 52% among the Mediterraneans.

Even though it wasn’t a weight-loss study, both groups lost weight.  The paleo dieters lost a bit more than the Mediterraneans: 5 kg vs 3.8 kg (11 lb vs 8.4 lb).  That’s fantastic weight loss for people not even trying.  Average starting weight of these 29 ischemic heart patients was 93 kg (205 lb).  Each intervention group had only 13 or 14 patients (I’ll let you figure out what happened to to the other two patients).

I blogged about this study population before.  Participants supposedly had diabetes or prediabetes, although certainly very mild cases (average hemoglobin A1c of 4.7% and none were taking diabetic drugs)

As I slogged through the research report, I had to keep reminding myself that this is a very small, pilot study.  So I’ll not bore you with all the details.

Bottom Line

This study suggests that the paleo diet may be particularly helpful for weight loss in heart patients.  No one knows how results would compare a year or two after starting the diet.  The typical weight-loss pattern is to start gaining the weight back at six months, with return to baseline at one or two years out.

Greek investigators found a link between the Mediterranean diet and better clinical outcomes in known ischemic heart disease patients.  On the other hand, researchers at the Heart Institute of Spokane found the Mediterranean diet equivalent to a low-fat diet in heart patients, again in terms of clinical outcomes.  U.S. investigators in 2007 found a positive link between the Mediterranean diet and lower rates of death from cardiovascular disease and cancer. 

We don’t yet have these kinds of studies looking at the potential benefits of the paleo diet.  I’m talking about hard clinical endpoints such as heart attacks, heart failure, cardiac deaths, and overall deaths.  The paleo diet definitely shows some promise.

I also note the Swedish investigators didn’t point out that weight loss in overweight heart patients may be detrimental.  This is the “obesity paradox,” called “reverse epidemiology” at Wikipedia.  That’s a whole ‘nother can o’ worms.

Keep your eye on the paleo diet.

Steve Parker, M.D.

Reference: Jönsson T, Granfeldt Y, Erlanson-Albertsson C, Ahrén B, & Lindeberg S (2010). A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease. Nutrition & metabolism, 7 PMID: 21118562

Gary Taubes’s new book, Why We Get Fat: And What To Do About It, comes on the market later this month.  I give it five stars per Amazon.com’s ranking system (I love it).

♦   ♦   ♦

At the start of my medical career over two decades ago, many of my overweight patients were convinced they had a hormone problem causing it.  I carefully explained that’s rarely the case.  As it turns out, I may have been wrong.  And the hormone is insulin.

Mr. Taubes wrote this long-awaited book for two reasons: 1) to make the ideas in his 2007 masterpiece (Good Calories, Bad Calories) more accessible to the public, and 2) to speed up the process of changing conventional wisdom on overweight.  GCBC was the equivalent of a college-level course on nutrition, genetics, history, politics, science, physiology, and biochemistry. Many nutrition science geeks loved it while recognizing it was too difficult for the average person to digest.

Paradigm Shift

The author hopes to convince us that “We don’t get fat because we overeat; we overeat because we’re getting fat.”  We need to think of obesity as a disorder of excess fat accumulation, then ask why the fat tissue isn’t regulated properly.  A limited number of hormones and enzymes regulate fat storage; what’s the problem with them?

Mr. Taubes makes a great effort convince you the old “energy balance equation” doesn’t apply to fat storage.  You remember the equation: eat too many calories and you get fat, or fail to burn up enough calories with metabolism and exercise, and you get fat.  To lose fat, eat less and exercise more.  He prefers to call it the “calories-in/calories-out” theory.  He admits it has at least a little validity.  Problem is, the theory seems to have an awfully high failure rate when applied to weight management over the long run.  We’ve operated under that theory for the last half century, but keep getting fatter and fatter.  So the theory must be wrong on the face of it, right?  Is there a better one?

So, Why DO We Get Fat?

Here is Taubes’s explanation.  The hormone in charge of fat strorage is insulin; it works to make us fatter, building fat tissue.  If you’ve got too much fat, you must have too much insulin action.  And what drives insulin secretion from your pancreas?  Dietary carbohydrates, especially refined carbs such as sugars, flour, cereal grains, starchy vegetables (e.g., corn, beans, rice, potatoes), liquid carbs.  These are the “fattening carbs.”  Dozens of enzymes and hormones are at play either depositing fat into tissue, or mobilizing the fat to be used as energy.  It’s an active process going on continously.  Any regulatory derangement that favors fat accumulation will CAUSE gluttony (overeating) or sloth (inactivity).  So it’s not your fault. 

What To Do About It

Cut back on carb consumption to lower your fat-producing insulin levels, and you turn fat accumulation into fat mobilization.

Before you write off Taubes as a fly-by-night crackpot, be aware that he’s received three Science-in-Society Journalism Awards from the National Association of Science Writers.  He’s a respected, professional science writer.  Having read two of his books, it’s clear to me he’s very intelligent.  If he’s got a hidden agenda, it’s well hidden.

One example  illustrates how hormones control growth of tissues, including fat tissue.  Consider the transformation of a skinny 11-year-old girl into a voluptuous woman of 18. Various hormones make her grow and accumulate fat in the places we now see curves.  The hormones make her eat more, and they control the final product.  The girl has no choice.  Same with our adult fat tissue, but with different hormones. If some derangement is making us grow fatter, it’s going to make us more sedentary (so more energy can be diverted to fat tissue) or make us overeat, or both.  We can’t fight it.  At not least very well, as you can readily appreciate if look at the people around you at any American shopping mall.

This’N'That

Taubes’s writing is clear and persuasive.  He doesn’t beat you over the head with his conclusions. He lays out a logical series of facts and potential connections and explanations, helping you eventually see things his way.  If insulin controls fat storage by building and maintaining fat tissue, and if carboydrates drive insulin secretion, then the way to reduce overweight and obesity is carbohydrate-restricted eating, especially avoiding the fattening carbohydrates.  I’m sure that’s true for many folks, perhaps even a majority.

If you’re overweight and skeptical about this approach, you could try out a very-low-carb diet for a couple weeks or a month at little expense and risk (but not zero risk).  If Mr. Taubes and I are right, there’s a good chance you’ll lose weight.  At the back of the book is a university-affiliated low-carb eating plan.

If cutting carb consumption is so critical for long-term weight control, why is it that so many different diets—with no focus on carb restriction—seem to work, if only for the short run?  Taubes suggests it’s because nearly all diets reduce carb consumption to some degree, including the fattening carbs.  If you reduce your total daily calories by 500, for example, many of those calories will be from carbs.  Simply deciding to “eat healthy” works for some people: stopping soda pop, candy bars, cookies, desserts, beer, etc.  That cuts a lot of fattening carbs right there.

Losing excess weight or controlling weight by avoiding carbohydrates was the conventional wisdom prior to 1960, as documented by Mr. Taubes.  Low-carb diets for obesity date back almost 200 years.  The author attributes many of his ideas to German internist Gustav von Bergmann (1908).   

Taubes discusses the Paleolithic diet, mentioning that the average paleo diet derived about a third of total calories from carbohdyrates (compared to the standard American diet’s 55% of calories from carb).  My prior literature review  found 40-45% of paleo diet calories from carbohydrate.  I’m not sure who’s right.

Minor Bone of Contention RE: Coronary Heart Disease

Mr. Taubes provides numerous scientific references to back his assertions.  I checked out one in particular because it didn’t sound right.  Some background first. 

Reducing our total fat and saturated fat consumption over the last 40 years was supposed to lower our LDL cholesterol, thereby reducing the burden of coronary heart disease, which causes heart attacks.  Instead, we’ve experienced the obesity epidemic as those fats were replaced by carbohydrates.  Taubes mentions a 2009 medical journal article by Kuklina et al, in which Taubes says Kuklina points out the number of heart attacks has not decreased as we’ve made these diet changes.  Kuklina et al don’t say that.  In fact, age-standardized heart attack rates have decreased in the U.S. during the last decade. 

Furthermore, autopsy data document a reduced prevalence of anatomic coronary heart disease in people aged 20-59 from 1979 to 1994, but no change in prevalence for those over 60. The incidence of coronary heart disease decreased in the U.S. from 1971 to 1998 (the latest reliable data).  Death rates from heart disease and stroke have been decreasing steadily over the last 40 years in the U.S.; coronary heart disease death rates are down by 50%.  I do agree with Taubes that we shouldn’t credit those improvements to reduced total and saturated fat consumption.  [Reduced trans fat consumption may play a role, but that’s off-topic.] 

I think Mr. Taubes would like to believe that coronary artery disease is either more severe or unchanged in the last few decades because of low-fat, high-carb eating.  That would fit nicely with some of his theories, but it’s not the case.  Coronary artery disease is better now thanks to a variety of factors, but probably not diet (setting aside the trans-fat issue).

Going Forward

Low-carb dieting was vilified over the last half century partly out of concern that the accompanying high fat consumption would cause premature heart attacks, strokes, and death.  We know now that total dietary fat and saturated fat have little to do with coronary heart disease and atherosclerosis (hardening of the arteries), which sets the stage for a resurgence of low-carb eating.  

I advocate Mediterranean-style eating as the healthiest, in general.  It’s linked with prolonged life and lower risk of heart disease, stroke, dementia, diabetes, and cancer.  On the other hand, obesity is a strong risk factor for premature death and development of heart disease, stroke, diabetes, and cancer.  If consistent low-carb eating cures the obesity, is it healthier than the Mediterranean diet?  Maybe so.  Would a combination of low-carb and Mediterranean be better?  Maybe so.  I’m certain Mr. Taubes would welcome a decades-long interventional study comparing low-carb with the Mediterranean diet.  But that’s probably not going to happen in our lifetimes. 

Gary Taubes rejects the calories-in/calories-out theory of overweight that hasn’t done a very good job for us over the last 40 years.  Taubes’s alternative ideas deserve serious consideration.   

Steve Parker, M.D.

References:
Coronary heart disease autopsy data:  American Journal of Medicine, 110 (2001): 267-273.
Reduced heart attacks:  Circulation, 12 (2010): 1,322-1,328.
Reduced incidence of coronary heart disease:  www.UpToDate.com, topic: “Epidemiology of Coronary Heart Disease,” accessed December 11, 2010.
Death rates for coronary heart disease:  Journal of the American Medical Association, 294 (2005): 1,255-1,259.

Disclosure:  I don’t know Gary Taubes.  I requested from the publisher and received a free advance review copy of the book.  Otherwise I received nothing of value for this review.

Disclaimer:   All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.  Always consult your personal physician before making any dietary or exercise changes.

MedPageToday reported October 8, 2010, that Abbott is voluntarily removing Meridia from the U.S. market.  I had written on September 8 about the higher incidence of stroke and heart attack in Meridia users who had underlying cardiovascular disease.

Meridia, also known as sibutramine, has an estimated 100,000 users in the U.S.  Abbott recommends that they stop taking the drug and consult their physicians about other weight-loss programs.

Here are a some options I like:

1. Advanced Mediterranean Diet
2. Ketogenic Mediterranean Diet
3. Low-Carb Mediterranean Diet

This would be a good time for Meridia ex-users to review “Prepare to For Weight Loss.”

Steve Parker, M.D.

The weight-loss drug sibutramine (Meridia) should be withdrawn from the U.S. market, suggests an editorialist in the September 2, 2010, New England Journal of Medicine.  Based on a clinical study in the same issue, it’s more accurate to conclude that sibutramine shouldn’t be prescribed for people who aren’t supposed to be taking it in the first place.

Sibutramine is sold in the U.S. as Meridia and has been available since 1997.  Judging from the patients I run across, it’s not a very popular drug.  Why not?  It’s expensive and most people don’t lose much weight.

The recent multi-continent SCOUT trial enrolled 9,800 male and female study subjects at least 55 years old (average age 63) who had either:

1. History of cardiovascular disease (here defined as coronary artery disease, stroke, or peripheral artery disease)
2. Type 2 diabetes plus one or more of the following: high blood pressure, adverse cholesterol levels, current smoking, or diabetic kidney disease.
3. Or both of the above (which ended up being 60% of the study population)`.

Here’s a problem from the get-go.  For years, Meridia’s manufacturer and the U.S. Food and Drug Administration have told doctors they shouldn’t use the drug in patients with history of cardiovascular disease.  It’s not the scary “black box warning,” but it’s clearly in the package insert of full prescribing information.

Half the subjects were randomized to sibutramine 10 mg/day and the other half to placebo.  All were instructed in diet and exercise aiming for a 600 calorie per day energy deficit.  They should lose about a pound a week if they followed the program.  Average follow-up was 3.4 years.

What Did the Researchers Find?

Forty percent of both drug and placebo users dropped out of the study, a very high rate.

As measured at one year, the sibutramine-users averaged a weight loss of 9.5 pounds (4.3 kg), the majority of which was in the first 6 weeks.  After the first year, they tended to regain a little weight, but kept most of it off.

Death rates were the same for sibutramine and placebo.

Sibutramine users with a history of cardiovascular disease had a 16% increase in non-fatal heart attack and stroke compared to placebo.  To “cause” one heart attack or stroke in a person with known cardiovascular disease, you would have to treat 52 such patients.

Folks in the “diabetes plus risk factor(s)” group who took sibutramine had no increased risk of heart attack or stroke.

So What?

Average weight loss with sibutramine isn’t much.  Nothing new there.  [Your mileage may vary.]

People with cardiovascular disease shouldn’t take sibutramine.  Nothing new there.

An FDA advisory panel reviews sibutramine in mid-September.  Are they likely to recommend withdrawal of the drug from the marketplace?  No.  They’ll remind doctors not to use it in patients with cardiovascular disease, and perhaps phrase that as a “black box warning.”

Steve Parker, M.D.

Reference:  James, W. Philip, et al.  Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects.  New England Journal of Medicine, 363 (2010): 905-917.

 For overweight and obese women, loss of between five and 10% of body weight significantly reduces urine leakage.  According to the research report in last month’s Obstetrics & Gynecology journal, weight loss should be the first approach to urine leakage in overweight and obese women.

The other word for urine leakage is incontinence: an involuntary loss of urine.  It’s a major problem that isn’t much talked about.  It’s not exactly dinner-party conversation material.  You can imagine its effect on quality of lifeIn the U.S., leakage of urine on at least a weekly basis is reported byone in 10 women and one in 20 men.  It’s more common at higher ages and in women.  Just looking at non-pregnant women, incontinence affects 7% of women aged 20-39, 17% of those aged 40-59, and 23% of women 60-79 years old.

The study at hand involved 338 overweight and obese women: average age 53 (minimum of 30), average body mass index 36, average weight 92 kg (202 lb).  For participation, they had to have at least 10 incontinence episodes per week.  On average, they reported 24 leakage episodes per week (10 stress incontinence, 14 urge incontinence).  All women were given a “self-help incontinence behavioral booklet with instructions for improving bladder control.”  They were randomized to two different weight-loss programs, but I won’t bore you with the details.  The diets were the standard reduced-calorie type.  One diet group had many more meetings than than the other.

The women kept diaries of leakage, and even collected urine soaked pads for weighing.

Results

Eight-five percent of the women completed the 18-month study.

By six months, 89 of the women has lost five to 10% of body weight; 84 lost over 10%.  As expected, when measured at 18 months, only 61 women were in the “five to 10% loss” category; 71 were in the “over 10%” group. 

Greater amounts of weigh loss were linked to fewer episodes of leakage.  Maximal improvement in leakage episodes were seen in the women who lost between five and 10% of body weight, with no additional benefit to greater degrees of weight loss, generally.

Women who lost 5-10% of their body weight were two to four times more likely to achieve at least a 70% redcution in total and urge incontinent episode frequency compared with women who gained weight at 6, 12, and 18 months.

Weight loss works better for stress incontinence than for urge incontinence.

Three of every four women who lost five to 10% of body weight said they were moderately or very satisfied with their improved bladder control.

Bottom Line

Weight loss is usually not a cure for incontinence, but a reasonable management option for overweight and obese women.  It’s going to take loss of five or 10% of body weight.  Other options  include drugs, surgery, Kegel exercises, and just living with it.

Five or 10% weight loss for a 200 pound woman is just 10 or 20 pounds.  That degree of weight loss is also linked to lower risk of diabetes and hypertension: even more reason go for it.  

Does it work for men?  Who knows?

Steve Parker, M.D.

Reference: Wing RR, Creasman JM, West DS, Richter HE, Myers D, Burgio KL, Franklin F, Gorin AA, Vittinghoff E, Macer J, Kusek JW, Subak LL, & Program to Reduce Incontinence by Diet and Exercise (2010). Improving urinary incontinence in overweight and obese women through modest weight loss. Obstetrics and gynecology, 116 (2 Pt 1), 284-92 PMID: 20664387

I answered this question recently at the Diabetic Mediterranean Diet Blog, based on research from the Department of Pediatrics, University of Colorado.

It’s an important question.  Childhood obesity in the U.S. tripled from the early 1980s to 2000, ending with a 17% obesity rate.  Overweight and obesity together describe 32% of U.S. children.  Some experts believe this generation of kids will be the first in U.S. history to suffer a decline in life expectancy, related to obesity.

Steve Parker, M.D., author of The Advanced Mediterranean Diet

Dieters on low-fat and low-carb diets both lost the same amount of weight after two years, according to a just-published article in Annals of Internal Medicine.  Both groups received intensive behavioral treatment, which may be the key to success for many.  Low-carb eating was clearly superior in terms of increased HDL cholesterol, which may help prevent heart disease and stroke.

The study was funded by the National Institutes of Health and was carried out in Denver, St. Louis, and Philadelphia.

How Was It Done?

Healthy adults aged 18-65 were randomly assigned to either a low-fat or low-carbohydrate diet.  Average age was45.  Average body mass index was 36 (over 25 is overweight; over 30 is obese).  Of the 307 participants, two thirds were women.  People over 136 kg (299 lb) were excluded from the study—I guess because weight-loss through dieting is rarely successful at higher weights. 

The low-carb diet:  Essentially the Atkins diet with a prolonged induction phase (12 weeks instead of two).  Started with maximum of 20 g carbs daily, as low-carb vegetables.  Increase carbs by 5 g per week thereafter as long as weight loss progressed as planned.  Fat and protein consumption were unlimited.  The primary behavioral goal was to limit carb consumption.

The low-fat diet:  Calories were limited to 1200-1500 /day (women) or 1500-1800 (men).  [Those levels in general are too low, in my opinion.]  Diet was to consist of about 55% of calories from carbs, 30% from fat, 15% from protein.  The primary behavioral goal was to limit overall energy (calorie) intake. 

Both groups received frequent, intensive in-person group therapy (lead by dietitians and psychologists) periodically over two years, covering such topics as self-monitoring, weight-loss tips, management of weight regain and noncompliance with assigned diet.  Regular walking was recommended.

Body composition was measured periodically with dual X-ray absorptiometry.

What Did They Find?

Both groups lost about 11% of initial body weight, but tended to regain so that after two years, both groups average losses were only 7% of initial weight.  Weight loss looked a little better at three months in the low-carb group, but it wasn’t statistically significant. 

The groups had no differences in bone density or body composition.

No serious cardiovascular illnesses were reported by participants.  During the first six months, the low-carb group reported more bad breath, hair loss, dry mouth, and constipation.  After six months, constipation in the low-carb group was the only symptom difference between the groups.

During the first six months, the low-fat group had greater decreases in LDL cholesterol (with potentially less risk of heart disease), but the difference did not persist for one or two years.

Increases in HDL cholesterol (potentially heart-healthy) persisted throughout the study for the low-carb group.  The increase was 20% above baseline.

About a third of participants in both groups dropped out of the study before the two years were up.  [Not unusual.]

My Comments

Contrary to several previous studies that suggested low-carb diets are more successful than low-fat, the study at hand indicates they are equivalent as long as dieters get intensive long-term group behavioral intervention. 

Low-carb critics warn that the diet will cause osteoporosis, a dangerous thinning of the bones that predisposes to fractures.  This study disproves that.

Contrary to widespread criticism that low-carb eating—with lots of fat and cholestrol— is bad for your heart, this study notes a sustained elevation in HDL cholesterol (”good cholesterol”) on the low-carb diet over two years.  This also suggests the low-carbers  followed the diet fairly well.  The investigators also note that low-carb eating tends to produce light, fluffy LDL cholesterol, which is felt to be less injurious to arteries compared to small, dense LDL cholesterol.

A major strength of the study is that it lasted two years, which is rare for weight-loss diet research.

A major weakness is that the investigators apparently didn’t do anything to document the participants’ degree of compliance with the assigned diet.  It’s well known that many people in this setting can follow a diet pretty well for two to four months.  After that, adherence typically drops off as people go back to their old habits.  The group therapy sessions probably improved compliance, but we don’t know since it wasn’t documented. 

How often do we hear “Diets don’t work.”  Well, that’s just wrong.

Overall, it’s an impressive study, and done well. 

Individuals wishing to lose weight on their own can’t replicate these study conditions because of the in-person behavioral intervention component.  There are lots of self-help calorie-restricted balanced diets (e.g., Sonoma Diet, The Zone, Thin For Life,  Advanced Mediterranean Diet) and low-carb diets (e.g., the Atkins Diet,  the Low-Carb Mediterranean or Ketogenic Mediterranean Diets).  On-line support groups—e.g., Low Carb Friends and SparkPeople and 3 Fat Chicks on a Diet—could supply some necessary behavioral intervention strategies and support.  

Choosing a weight-loss program is not as easy as many think.  [Well, I’ll admit that choosing the wrong one is easy.]  I review the pertinent issues in my “Prepare for Weight Loss” page.

Steve Parker, M.D.

Reference: Foster GD, Wyatt HR, Hill JO, Makris AP, Rosenbaum DL, Brill C, Stein RI, Mohammed BS, Miller B, Rader DJ, Zemel B, Wadden TA, Tenhave T, Newcomb CW, & Klein S (2010). Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: a randomized trial. Annals of internal medicine, 153 (3), 147-57 PMID: 20679559

Compared to the low-fat American Heart Association diet, the traditional Mediterranean diet rich in olive oil has more capacity to counteract potentially harmful “free radicals” and “reactive oxygen species” in our bodies, according to researchers at the University of Navarra in Spain.

Our tissues normally contain free radicals and reactive oxygen species, which are intrinsic to cell metabolism.  They serve useful purposes.  In excessive amounts, however, many believe they cause ”oxidative damage” and thereby contribute to chronic degenerative conditions such as atherosclerosis, aging, dementia, and cancer.

Antioxidants are thought to neutralize free radicals and reactive oxygen species, which may lead to better health.

The PREDIMED study is an ongoing Spanish project testing the heart-protective effects of the Mediterranean diet in high-risk people over the course of four years.  The three intervention groups are 1) Medi diet plus supplemental virgin olive oil, 2) Medi diet plus extra tree nuts, and 3) low-fat American Heart Association diet.

After three years of follow-up, the researchers measured “total antioxidant capacity” in the bloodstream of a subset of the PREDIMED participants.

They found that the two Mediterranean diet groups had significantly greater total antioxidant capacity, about 50% more than the low-fat control group.  Within the Medi + olive oil group, the participants with the highest levels of antioxidant capacity actually tended to lose weight, an association not seen in the other groups.

The Researchers’ Conclusions

Mediterranean diet, especially rich in virgin olive oil, is associatied with higher levels of plasma antioxidant capactiy.  Plasma total antioxidant capacity is related to a reduction in body weight after three years of intervention in a high cardiovascular risk population with a Mediterranean-style diet rich in virgin olive oil.

In other words, the Mediterranean diet with virgin olive oil may help you keep your weight under control, and the antioxidant capacity may contribute to the well-documented health benefits of the diet.

Steve Parker, M.D.

PS:  It’s impossible to tell from this report just how much weight loss was seen in the high-TAC Medi+olive oil subjects.  I doubt it was much.  Baseline body mass index for all participants was around 29, so they were overweight and just a shade under obese.

PPS:  Both the Ketogenic Mediterranean and Diabetic Mediterranean Diets mandate minimal amounts of olive oil consumption, with no upper limit.

Reference: Razquin, C., Martinez, J., Martinez-Gonzalez, M., Mitjavila, M., Estruch, R., & Marti, A. (2009). A 3 years follow-up of a Mediterranean diet rich in virgin olive oil is associated with high plasma antioxidant capacity and reduced body weight gain European Journal of Clinical Nutrition, 63 (12), 1387-1393 DOI: 10.1038/ejcn.2009.106

Losing excess weight is easier than keeping it off.

Neither is exactly a walk in the park.

Prevention of weight regain is the most problematic area in the field of weight management.  You may have heard that “diets don’t work,” but they do.  Many different weight loss programs work short-term, if “work” is defined as loss of five, 10, or more pounds while you adhere to the program for several weeks or months.  The problem is that the lost pounds usually return.

Why?  You get bored with the diet, or your willpower flags, or the diet simply stops working, or the transition from weight loss to maintenance is unclear, or you just feel too bad to go on, or you lose your commitment, or you take a job as a taste tester for Baskin-Robbins Ice Cream, or whatever. 

Most diets ultimately fail in the long run because people go back to their old habits. 

Read on for the secret to prevention of weight regain.  They apply to a majority of weight-loss methods, although many programs ignore this problem because the cure is a hard pill to swallow. 

Moving Ahead

For purposes of further discussion, I will assume that you have already lost excess weight down to your goal and now we must focus on staying thereabouts from here on out.  Finally down to your goal!  A grand accomplishment!  You’ve got a new wardrobe, or the old clothes fit again.  You have more energy and feel younger.  Maybe you cured or improved some health problems.  Perhaps you’re getting more attention from the opposite sex (ooh la la!). 

Our species’ scientific name is Homo sapiens.  It is from the Latin sapere, which means “to be wise.”  Wisdom is the ability to make correct judgments and decisions.  Undoubtedly, your success at weight loss required correct judgments and decisions.  You are not done yet.  You will need sustained wisdom to avoid weight regain.

Be wise about this especially: you can never again eat all you want, whenever you want, over sustained periods of time.  

Now that you have reached your goal weight, you must restrain yourself on a daily basis.  Think about it.  You became overweight because you didn’t watch what you ate and didn’t exercise enough.  You can’t go back to your old ways.  Reject this advice, and you have a 100 percent chance of regaining your lost weight. 

Have you heard of the Energy Balance Equation?

Calorie Intake minus Calories Burned

         =  Change in Body Fat

You have been able to lose fat weight because you ate less energy (calories) than your body required for metabolism and physical activity.  Your body remedied the energy deficit by converting fat into energy.  A pound of fat contains 3,500 calories of energy.  If you lost a pound per week, your body on average converted 500 calories of fat daily into energy (7 days x 500 calories = 3,500 calories = 1 pound of fat). 

Now that you are at your goal weight and want to stay there, you need to add 500 calories per day back into the equation.  Add the calories by eating more food, exercising less, or a combination of the two. But if you add back more than 500, you will regain weight.

The true measure of a successful weight management program is not simply how much weight is lost, but whether the lost weight stays lost over the long run.  What distinguishes weight losers who keep the weight off from those who gain it back?  Two factors, mostly:

          1.  Restrained eating
          2.  Regular physical activity.

“Successful losers” apply self-restraint on an almost daily basis, avoiding food that they know will lead to weight regain.  They limit how much they eat.  They consciously choose not to return to their old eating habits, despite urges to the contrary.  The other glaring difference is that, compared to regainers, the successful losers remain physically active.  They exercised while losing weight, and continue to exercise in the maintenance phase of their program.  This is true in at least eight out of 10 cases.  It’s clear that regular exercise is not always needed, but it dramatically increases your chances of long-term success. 

In a nutshell, my maintenance phase prescription for you is: Keep exercising, and eat a little more.  Keep exercising, and eat a little more.

Go out of your way to be physically active for 30 to 45 minutes on at least four days per week, if not all days.  Walking is fine.  The more you exercise, the more you can eat without getting fat again. 

At the end of your weight-loss phase and the beginning of the maintenance phase, it is surprisingly easy to start overeating.  Forewarned is forearmed.  Avoid this landmine any way you can.  It helps to continue monitoring food consumption and exercise on your food diary while eating an additional 200–500 calories per day.  Continue weighing daily.  Keep exercising.  After a month or two of this regimen, you’ll have an intuitive sense of what and how much you should be eating without regaining weight.  Then stop the daily log routine. 

Another option for transition to the maintenance phase: if you have been exercising regularly but loathe it, you could stop exercising and stay on your current calorie level diet.  In other words, don’t start eating more.  See what happens with your weight.  Perhaps you could later eat an extra 100 to 200 daily calories without gaining weight.  Continue recording your daily intake and weight for a couple months.  

Weigh yourself daily during the first two months of your maintenance-of-weight-loss phase. After that, weigh weekly.  Daily weights will remind you how hard you worked to achieve your goal.  When you look now at a brownie, candy bar, or piece of pie, you ask yourself, “Do I really want to walk an extra hour or jog an extra three miles today to burn off those calories?” If so, enjoy. Otherwise, forego the unneeded calories. 

Be aware that you might regain five or 10 pounds of fat now and then.  You probably will.  It’s not the end of the world.  It’s human nature.  You’re not a failure; you’re human.  

But draw the line and get back on your old weight-loss program for one or two months.  Analyze and learn from the episode.  Why did it happen?  Slipping back into your old ways? Slacking off on exercise?  Too many special occasion feasts?  Allowing junk food back into the house?  Learn which food item is your nemesis—the food that consistently torpedoes your resolve to eat right.  For example, I have two—candy, and sweet baked goods such as cookies and muffins.  If I just look at them I add a pound.  Remember an old ad campaign for a potato chip: “Betcha can’t eat just one!”?  Well, I can’t eat just one cookie.  So I don’t get started.  I might eat one if it’s the last one available.  Or I satisfy my sweet craving with fresh fruit or a diet soda.  Just as a recovering alcoholic can’t drink any alcohol, perhaps you should totally abstain from…?  You know your own personal gastronomic Achilles heel.  Or heels.  Experiment with various strategies for vanquishing your nemesis. 

It’s OK to overindulge in food infrequently (10–12 times per year), on special occasions such as birthdays, wedding anniversaries, holidays.  But you must counteract the extra calories by cutting down intake or by exercising more, either before or after the feast.  No big deal.

Click to read additional ideas on prevention of weight regain.

Steve Parker, M.D.