Archive for March, 2009
U.S. researchers found an association between decreased all-cause mortality - i.e., the chance of dying from anything - and religiosity.
The Women’s Health Initiative observational study has spawned numerous scientific research articles. It generated data based on a survey of nearly 95,000 U.S. women between 50 and 79 years old at the start of the study. Average follow-up time was 7.7 years.
The survey included religiosity variables: religious affiliation, frequency of religious service attendance, and religious strength and comfort.
These variables were associated with 10 to 20% reductions in all-cause mortality compared to non-religious women or those who expressed their religiosity in other ways. For instance, weekly religious service attendance was associated with a 20% lower risk of death.
Nobody knows if the results apply to men, but I suspect they do. You might say I have faith.
Reference: Schnall, Eliezer, et al. The relationship between religion and cardiovascular outcomes and all-cause mortality in the women’s health initiative study. Psychology and Health, November 17, 2008. DOI: 10.1080/08870440802311322
Vitamin D deficiency is common in older folks due to low dietary intake, reduced ability of skin to make vitamin D, and restricted sunlight exposure.
Low vitamin D levels are associated with
- increased risk of fractures
- higher death rates
- tendency to fall
- type 2 diabetes
- several cancers
- heart attacks
- multiple sclerosis
- and, classically, rickets
A few small clinical studies have associated low vitamin D levels with cognitive impairment and dementia. The longer you live, the greater your chance of developing cognitive impairment and dementia.
A study published in the Journal of Geriatric Psychiatry and Neurology last month found low levels of vitamin D associated with increased odds of cognitive impairment, which is often a precursor to dementia. Study participants were 1,766 adults aged 65 years and older form the Health Survey for England 2000, a nationally representative population-based study.
Blood levels of 25-hydroxyvitamin D were analyzed and compared to participants’ performance scores on the Abbreviated Mental Test. The test has 10 items, primarily covering orientation in time and space, memory, and attention. Overall, 212 participants (12%) were cognitively impaired. The lower the vitamin D level, the greater the odds of impairment. For example, people with the lowest quarter of vitamin levels were over twice as likely to have cognitive impairment compared to the highest quarter.
The study authors point out that a number of studies seem to contradict their results, and they explain the differences in the various studies and possible reasons for the discordant results. Nevertheless, they think their results are more valid.
How could vitamin D, best known for healthy bone effects, help preserve cognitive function? The authors write:
Vitamin D may also be of interest in the prevention of neurodegenerative diseases as ample evidence from in vitro and animal experiments suggests an important role in the expression of neurotrophic factors, the stimulation of adult neurogenesis, calcium homeostasis, and detoxification.
Vitamin D is starting to sound like a miracle drug, if you’ve been paying attention to all the recent research. But let’s not forget all the hope and hype regarding the benefits of various supplements over the last decade that ended up disappointing us: vitamin E, vitamin C, Foltx, vitamin A analogs, and others.
I’m wondering if a vitamin D level should be part of the dementia evaluation process. It is not at this point. How about offering the test to everybody starting at age 50?
Vitamin D supplements are cheap, well-tolerated, and effective in treating at least some deficiency sydromes, such as vitamin D-deficient osteoporosis.
I certainly agree with the researchers, who write:
Further research is warranted to investigate if vitamin D supplementation is a cost-effective and safe way of reducing the incidence of cognitive impairment [and dementia] in the growing elderly population around the world.”
Many people over 50 are already taking vitamin D for bone preservation. This study provides another reason to continue it.
Llewellyn, David; Langa, Kenneth; and Lang, Iain. Serum 25-Hydroxyvitamin D Concentration and Cognitive Impairment. Journal of Geriatric Psychiatry and Neurology, Epub ahead of print on February 4, 2009, as doi: 10.1177/0891988708327888
I am pleased to announce that in January of this year I met the accreditation criteria of the Health on the Net Foundation’s Code of Conduct for medical and health Web sites.
From the HON website:
The Health On the Net Foundation (HON) promotes and guides the deployment of useful and reliable online health information, and its appropriate and efficient use. Created in 1995, HON is a non-profit, non-governmental organization, accredited to the Economic and Social Council of the United Nations. For twelve years, HON has focused on the essential question of the provision of health information to citizens, information that respects ethical standards. To cope with the unprecedented volume of healthcare information available on the Net, the HONcode of conduct offers a multi-stakeholder consensus on standards to protect citizens from misleading health information.
Here are HONcode criteria I pledge to uphold:
- Authoritative. Any medical or health advice provided and hosted on this site will only be given by medically trained and qualified professionals unless a clear statement is made that a piece of advice offered is from a non-medically qualified individual or organisation.
- Complementarity. The information provided on this site is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her existing physician.
- Privacy. Confidentiality of data relating to individual patients and visitors to a medical/health Web site, including their identity, is respected by this Web site. The Web site owners undertake to honour or exceed the legal requirements of medical/health information privacy that apply in the country and state where the Web site and mirror sites are located.
- Attribution. Where appropriate, information contained on this site will be supported by clear references to source data and, where possible, have specific HTML links to that data. The date when a clinical page was last modified will be clearly displayed (e.g. at the bottom of the page).
- Justifiability. Any claims relating to the benefits/performance of a specific treatment, commercial product or service will be supported by appropriate, balanced evidence in the manner outlined above in Principle 4.
- Transparency. The designers of this Web site will seek to provide information in the clearest possible manner and provide contact addresses for visitors that seek further information or support. The Webmaster will display his/her E-mail address clearly throughout the Web site.
- Financial disclosure. Support for this Web site will be clearly identified, including the identities of commercial and non-commercial organisations that have contributed funding, services or material for the site.
- Advertising policy. If advertising is a source of funding it will be clearly stated. A brief description of the advertising policy adopted by the Web site owners will be displayed on the site. Advertising and other promotional material will be presented to viewers in a manner and context that facilitates differentiation between it and the original material created by the institution operating the site.
If you notice any violations of the code, please contact me via email (see Contact page) or contact the Health on the Net Foundation.
I frequently check in at CalorieLab for up-to-date nutrition news.
Karen Collins, M.S., R.D., C.D.N., is a guest contributor there today, writing about the potential health benefits of nuts. I was aware of the cardiovascular benefits; she taught me about possible salutary effects on cancer and diabetes.
From my own literature review, the cardiac benefits are associated with a nut ”dose” of three to five 1-ounce servings a week.
Last December, I blogged about reversal of metabolic syndrome with a Mediterranean Diet supplemented with nuts.
I recommend Ms. Collins’ article to you.
Albert, Christine, et al. Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health Study. Archives of Internal Medicine, 162, (2002): 1,382-1,387.
The Million Women Study recently looked at the association between alcohol consumption and the incidence of various cancers in middle-aged women in the United Kingdom.
Here’s the conclusion from the abstract in the Journal of the National Cancer Institute:
Low to moderate alcohol consumption in women increases the risk of certain cancers. For every additional drink regularly consumed per day, the increase in incidence up to age 75 years per 1000 for women in developed countries is estimated to be about 11 for breast cancer, 1 for cancers of the oral cavity and pharynx, 1 for cancer of the rectum, and 0.7 each for cancers of the esophagus, larynx and liver, giving a total excess of about 15 cancers per 1000 women up to age 75.
Other cancers seemed to be reduced by increasing levels of alcohol consumption: thyroid, non-Hodgkin lymphoma, renal cell carcinoma.
Comparing wine with other alcohol types, no differences in cancer risks were found.
Low to moderate alcohol consumption is associated with prolonged life, lesser risk of dementia, and lower rates of cardiovascular disease. The article abstract doesn’t mention these issues, nor the possibility that the benefits of judicious alcohol consumption may outweigh the cancer risks.
Allen, Naomi, et al. Moderate Alcohol Intake and Cancer Incidence in Women. Journal of the National Cancer Institute, 101 (2009): 296-305.
Lauer, Michael and Sorlie, Paul. Alcohol, Cardiovascular Disease, and Cancer: Treat With Caution. Journal of the National Cancer Institute, 101 (2009): 282-283.
Szwarc, Sandy. In Vino Veritas - Part Two. Junkfood Science blog, March 1, 2009. Accessed March 10, 2009. A quote from Ms. Szwarc regarding the Million Women Study:
The bottom line is that scary claims that “there is no level of alcohol consumption that can be considered safe,” simply was not supported by the data. This study actually found no credible link between alcohol consumption and cancers at all. Or, if you want to split hairs and believe the small computed numbers, it found that the lowest risk for cancers was associated with women drinking up to 1-2 drinks a day.
A recent study published in the Journal of the American Dietetic Association documents one way to change eating habits: exchange lists.
Your basic exhange list is a list of recommended foods, with serving sizes and frequencies. For example, I could give you note recommending you eat three pieces of fruit, four 1-cup servings of vegetables, and two tablespoons of healthy oils daily. Then I give you a list fruits, vegetables, and oils from which to choose. You decide which fruits to eat from the list, just be sure to eat three servings daily. One fruit is as good as the other: they are exchangeable. You check off your intake as you go through the day. People with diabetes have used exchange lists for years.
Researchers with the University of Michigan Health System plan to test a Mediterranean-style diet for breast cancer prevention. Several previous observational studies have associated the Mediterranean diet with lower rates of breast cancer (along with lower rates of colon, uterus, and prostate cancer). The researchers wondered how to get women to change their diet in the direction of a Greek-Mediterranean diet. They devised an exchange list to promote high intake of monounsaturated fats and fruits and vegetables. Would women follow it?
Sixty-nine women, ages 25 to 59, were enrolled to either continue their usual diet or to follow a six-month intervention diet designed to:
decrease usual fat intakes by about half and to replace those fats with olive oil and other high–monounsaturated fatty acid foods; increase fruit and vegetable intakes to 7 to 9 servings/day, depending on energy intake; and consume at least one serving per day each of culinary herbs and allium vegetables.
Allium vegetables include onions, leeks, chives, garlic, and shallots.
Dietitians designed a Mediterranean diet exchange list, specified exchange goals, and provided individualized telephone counseling. Counseling was in-person at the start of the study and three months later.
Here’s a quote from the University of Michigan Health System news release:
In this new study, specific suggestions in the exchange list included:
- 8-10 servings (or exchanges) each day of high monounsaturated fatty acid (MUFA), such as olive or hazelnut oil, avocado and macadamia nuts
- Limits on fats that are low in MUFA, such as corn oil, margarine, tahini, pine nuts and sesame seeds.
- One or more servings a day of dark green vegetables, such as broccoli, peas and spinach
- At least one exchange per day of garlic, onions and leeks
- One tablespoon or more per day of green herbs, such as basil, cilantro, peppermint and sage
- One or more servings a day of red vegetables, such as tomatoes, tomato sauce and salsa
- One or more servings a day of yellow or orange vegetables, such as carrots, red bell peppers and pumpkin
- One or more servings a day of other vegetables, such as artichokes, cucumber, green beans and sugar snap peas
- One or more servings a day of vitamin C fruits, such as oranges, mangoes and strawberries
- One or more servings a day of other fruits, such as apples, bananas and grapes
Compared to the non-intervention (control) group, the Mediterranean group:
- increased dietary monounsaturated fat by 48% (with no change in total fat intake)
- increased fruit and vegetable intake from 4 to 8.6 servings a day
Results demonstrated that counseling using the Mediterranean exchange list was effective for large dietary changes relative to the nonintervention group.
I can’t wait to see the larger prospective study regarding breast cancer reduction with a Greek-Mediterranean diet. But it will take years. And the dietary effects likely are cumulative over years of eating, not just six months. This is a start.
We have seen with weight-loss diets that people typically return to their old ways of eating six to twelve months after making a change. That’s why it’s so difficult to demonstrate irrefutably that one diet is healthier than another. How do you get 10,000 people to make major dietary changes and sustain them for 10-20 years, and another similar group of 10,000 people to make no changes? [After 20 years, you compare the health status of both groups.]
I suppose we could study prisoners serving life terms. Hmmm . . .
Many of us can’t wait 10 or 20 years for study results. We have to make food decisions now, based on the best available data.
Steve Parker, M.D.
Djuric, Zora, et al. Design of a Mediterranean Exchange List Diet Implemented by Telephone Counseling. Journal of the American Dietetic Association, 108 (2008): 2,059-2,065.
University of Michigan Health System news release, “Women double fruit, veggie intake with switch to Mediterranean diet,” December 17, 2008.
Ever heard of the Spanish Ketogenic Mediterranean Diet? It looks like a low-carb quasi-Mediterranean diet.
Researchers with the University of Cordoba in Spain studied 40 subjects eating a low-carb “Mediterranean” diet for 12 weeks. The results were strikingly positive.
A medical weight loss clinic was the source of 40 overweight subjects, 22 males and 19 females, average age 38, average body mass index 36.5, average weight 108.6 kg (239 lb). These folks were interested in losing weight, and were not paid to participate.
Nine subjects were not included in the final analysis due to poor compliance with the study protocol (3), the diet was too expensive (1), a traumatic car wreck (1), or were simply lost to follow-up (4). So all the data are pooled from the 31 subjects who completed the study.
Blood from all subjects was drawn just before the study began and again after 12 weeks of the diet.
Study diet: Low-carbohydrate, high in protein [and probably fat, too], unlimited in calories. Olive oil was the main source of fat (at least 30 ml daily). Maximum of 30 grams of carbohydrates daily as green vegetables and salad. 200-400 ml daily of red wine. The authors write:
Participants were permitted 3 portions (200 g/portion) of vegetables daily: 2 portions of salad vegetables (such as alfalfa sprouts, lettuce, escarole, endive, mushrooms, radicchio, radishes, parsley, peppers, chicory, spinach, cucumber, chard and celery), and 1 portion of low-carbohydrate vegetables (such as broccoli, cauliflower, cabbage, artichoke, eggplant, squash, tomato and onion). 3 portions of salad vegetables were allowed only if the portion of low-carbohydrate vegetables were not consumed. Salad dressing allowed were: garlic, olive oil, vinegar, lemon juice, salt, herbs and spices.
The minimum 30 ml of olive oil were distributed unless in 10 ml per principal meal (breakfast, lunch and dinner). Red wine (200–400 ml a day) was distributed in 100–200 ml per lunch and dinner. The protein block was divided in “fish block” and “no fish block”. The “fish block” included all the types of fish except larger, longer-living predators (swordfish and shark). The “no fish block” included meat, fowl, eggs, shellfish and cheese. Both protein blocks were not mixed in the same day and were consumed individually during its day on the condition that at least 4 days of the week were for the “fish block”.
Trans fats (margarines and their derivatives) and processed meats with added sugar were not allowed.
Vitamin and mineral supplements were given.
Subjects measured their ketosis state every morning with urine ketone strips.
- Body weight fell from 108.6 kg (239 lb) to 94.5 kg (209 lb), or 2.5 pounds per week
- Body mass index fell from 36.5 to 31.8
- Systolic blood pressure fell from126 to 109 mmHg
- Diastolic blood pressure fell from 85 to 75 mmHg
- Total cholesterol fell from 208 to 187 mg/dl
- LDL chol fell from 115 to 106 mg/dl
- HDL chol rose from 50 to 55 mg/dl
- Fasting glucose dropped from 110 to 93 mg/dl
- Triglycerides fell from 219 to 114 mg/dl
- No significant differences in male and female subjects
- No adverse reactions are mentioned
The SKMD [Spanish Ketogenic Mediterranean Diet] is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels. Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.
The researchers called this diet “Mediterranean” based on olive oil, red wine, fish, and vegetables.
What’s “Not Mediterranean” is the paucity of carbohydrates (including whole grains); lack of yogurt, nuts, and legumes; and the high meat/protein intake.
The emphasis on olive oil, red wine, and fish could make this healthier than other ketogenic diets.
Ketogenic diets are notorious for high drop-out rates compared to other diets. But several studies suggest greater short-term weight loss for people who stick with it. Efficacy and superiority are little different from other diets as measured at one year out.
Many of the metabolic improvements seen here might be duplicated with loss of 30 pounds (13.6 kg) over 12 weeks using any reasonable diet.
Average fasting blood sugars in these subjects was 109 mg/dl. Although not mentioned by the authors, this is in the prediabetes range. The diet reduced average fasting blood sugar to 93, which would mean resolution of prediabetes. Dropping body mass index from 36 to 32 by any method would tend to cure prediabetes.
Elevated blood sugar is one component of the “metabolic syndrome.” Metabolic syndrome was recently shown to be reversible with a Mediterranean diet supplemented with nuts.
I suspect this would be a good program for an overweight person with uncontrolled type 2 diabetes, too. But it has never been studied in a diabetic population. So, who knows for sure?
If you’re thinking about doing something like this, get more information and be sure to get your doctor’s approval first.
Update April 6, 2008:
I just had a delightful conversation with Jimmy Moore, of Livin’ La Vida Low-Carb fame regarding this study. I reviewed it again in preparation. It struck me that the Spanish Ketogenic Mediterranean Diet is probably higher in protein and lower in fat than many other ketogenic weight-loss diets. Since fish is emphasized over other animal-derived foods, it’s likely also lower in saturated fat. [In low-carb diets, carbohydrates are substituted with either fats or proteins.] I’m also convinced I will eventually have to review the validity of the dogmatic diet-heart hypothesis: Dietary saturated fat and cholesterol contribute to atherosclerosis and associated premature death from heart attacks and strokes.
Update September 25, 2009:
My Ketogenic Mediterranean Diet has much in common with the study at hand. One of several major differences is that it’s user-friendly and ready to implement as soon as you have your physician’s clearance. It’s posted at the Diabetic Mediterranean Diet Blog.
References and Additional Reading:
Perez-Guisado, J., Munoz-Serrano, A., and Alonso-Moraga, A. Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss. Nutrition Journal, 2008, 7:30. doi:10.1186/1475-2891-7-30 I like the idea behind Nutrition Journal. From the publisher’s website:
Nutrition Journal aims to encourage scientists and physicians of all fields to publish results that challenge current models, tenets or dogmas. The journal invites scientists and physicians to submit work that illustrates how commonly used methods and techniques are unsuitable for studying a particular phenomenon. Nutrition Journal strongly promotes and invites the publication of clinical trials that fall short of demonstrating an improvement over current treatments. The aim of the journal is to provide scientists and physicians with responsible and balanced information in order to improve experimental designs and clinical decisions.
With the advent of the Internet, has dawned a new way to exchange information and to publish biomedical journals. BioMed Central has been a pioneer in online publishing with Nutrition Journal being one of its many journals. Publication in Nutrition Journal offers many advantages over traditional paper publications; the journal offers free access to its articles; high quality and rapid peer-review; immediate publication; and most importantly, universal access to its content from virtually any place in the world.
Bravata, D.M., et al. Efficacy and safety of low-carbohydrate diets: a systematic review. Journal of the American Medical Association, 289 (2003): 1,837-1,850.
Gardner, C.D., et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. Journal of the American Medical Association, 297 (2007): 696-677.
Stern, L., et al. The effects of low-carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial. Annals of Internal Medicine, 140 (2004): 778-785.
Shai, Iris, et al. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. New England Journal of Medicine, 359 (2008): 229-241.
These guys are continually updating their website to help you eat healthier. The latest addition is essentially a souped-up food diary called “My Tracking.” After registering, you enter what kind and amount of food you eat, and My Tracking generates a detailed report of your overall diet composition, including total calories. Use it to monitor your progress.
Why do it? It’s well-established that food diaries, also called journals, improve success of people trying to lose excess weight. For details, see my November 7, 2008, blog post.
“OK, but how much is this going to cost me?” you ask. Zero.
Steve Parker, M.D.
On Feb. 26, 2009, I blogged about the recent New England Journal of Medicine article comparing diets of various macronutrient (fat, protein, carbohydrate) composition. Its conclusion: Cut back on calories and you will lose weight, regardless of macrontrient percentages.
A reader, Matt, brought up some interesting comments and questions. What follows will make little sense unless you read that Feb. 26 blog post.
If the study folks didn’t do the real low carb diet because they “knew” that ketosis wouldn’t occur, couldn’t they at least have tried it, since what they were trying to prove was a calorie is a calorie?
Looking at the menus, the diet that they are purporting as low carb is really nothing close to a real low carb diet. It is a slightly lower carb diet, and not high enough in fat to prove anything. 35% carb is not Atkins phase anything. For a participant consuming 1600 calories, that’s 140g carb — too high for anyone attempting to restrict carbohydrates for health.
Please comment on the fact that the highest carb diet provided the worst lipid improvement.
Following up a little more, there really is no inference whatsoever that can be made with regard to a low carb diet with this study. Did you read the sample menu? No low carb diet phase would have any of the following as a typical meal. You can tell by looking at the menus that they had to be really PC about a “high fat” diet as well. I mean skim milk on a low carb / high fat diet? Note my level of surprise by the ? and ! in the parens with each “typical meal” option:
1 poached egg
1/2 bagel (??)
4 oz apple juice (????!!!!)
skim (????) milk
1/2 cup spaghetti (??!!)
1/2 cup squash
1/2 cup peppers
1/2 cup mushrooms
1.5 T Olive Oil
1 small banana (????)
2 oz beef
1 small potato (????!!!!)
3/4 mixed veggies/legumes corn/carrots/lima/peas/green beans (???? since these are among the higher carb veggie choices)
1/2 cup cabbage
1 mini box raisins (??)
1 small apple (?????)
4 t Olive Oil
7 walnut halves
Skim (???) Milk
1 Graham cracker sheet (??????)
If you want a LC diet with what LC would consider a higher level of carbs (~60g) you need to do this:
2-4 poached eggs
2 T olive oil
1 cup whole milk
1/2 cup squash
1/2 cup peppers
1/2 cup mushrooms
2 T Olive Oil
4-6 oz fish
4-6 oz beef
3/4 mixed lower carb (cruciferous/leafy) veggies such as broccoli, collards or other greens,
1/2 cup cabbage
2 T Olive Oil
20 walnut halves
1/2 cup low carb fruit such as cantaloupe
1/2 cup strawberries
1 cup whole milk yogurt ot cottage cheese
Thanks for your thoughtful comments/questions, Matt.
You’re right: The “low-carb” diet they studied indeed was not very low-carb, as succinctly illustrated by the sample menu you provided. [I didn’t read the supplementary appendix myself.]
You mention that the “highest carb diet provided the worst lipid improvement.” It’s not that clear-cut.
[Lipid changes are on pages 865-7 of the article, for anyone following along. Conventional wisdom is that better cardiovascular health is associated, generally, with lower total cholesterols, higher HDL chol, lower total LDL chol, and lower triglycerides.]
The study had two low-fat diets, with either 55 or 65% of total calories derived from carbohydrates. The two high fat diets had either 35 or 45% of total calories from carbohydrates.
Total cholesterol levels dropped by about 3 mg/dl in the low-fat diets compared to “no change” in the high-fat diets (2-year values). Measured at 6 months, total chol levels were down by about 5.5 mg/dl in the low-fat groups, and about 3 mg/dl in the high-fat groups. Baseline total chol levels for the whole group averaged 202 mg/dl.
The authors on page 865 write:
All the diets reduced risk factors for cardiovascular disease and diabetes at 6 months and 2 years. At 2 years, the two low-fat diets and the highest-carbohydrate diet decreased low-density lipoprotein [LDL] cholesterol levels more than did the high-fat diets or lowest-carbohydrate diet.
The lowest-carb diet increased HDL chol more than the highest carb diet, but we’re only talking about a 2 mg/dl difference measured at 2 years. HDL rose in all groups. Average baseline HDL level for the entire study group was 49 mg/dl.
All diets decreased triglycerides similarly, by 12-17%.
The magnitude of these changes is not great, and I question whether clinically important. The take-home point for me is that low-carb eating may not be as atherogenic as warned by the medical community 15-20 years ago, judging purely from lipid changes. Other studies found similar numbers. But we’ve already agreed the this was not a serious trial of low-carb dieting.
The study authors write that HDL chol is a biomarker for carbohydrate intake: reducing dietary carbs tends to increase HDL chol levels, and vice versa. I had never seen it put this way before.
If I understand “Nutrient Intake per Day” in Table 2 correctly, the participants who were told to increase their percentage of calories from fat really didn’t do it: they reduced it by 3.5% (!?). The low-fat cohorts had more success with compliance.
Clearly, it’s quite difficult to get free-living people to change their macronutrient intake and sustain the change for even six months, much less two years. Would compliance have been better if subjects had been allowed to choose a diet according to their natural inclinations? Maybe.
If you want to keep me from popping into a Taco Bell or McDonald’s occasionally, you’ll probably have to move me to an Arctic research station.