July 16, 2008
Low Fat Diets Worst For Weight Control

Diets with more fats and protein seem take off more fat than diets low in fat.

NEW YORK, July 14, 2008 – A two-year study led by researchers from Ben-Gurion University of the Negev (BGU) reveals that low-carbohydrate and Mediterranean diets may be just as safe and effective in achieving weight loss as the standard, medically prescribed low-fat diet, according to a new study published in the prestigious New England Journal of Medicine.

The study was conducted by BGU and the Nuclear Research Center in Dimona, Israel, in collaboration with Harvard University, The University of Leipzig, Germany and the University of Western Ontario, Canada.

In the two-year study, 322 moderately obese people were intensively monitored and were randomly assigned one of three diets: a low-fat, calorie-restricted diet; a Mediterranean calorie-restricted diet with the highest level of dietary fiber and monounsaturated/saturated fat; or a low-carbohydrate diet with the least amount of carbohydrates, highest fat, protein, and dietary cholesterol. The low-carb dieters had no caloric intake restrictions.

Although participants actually decreased their total daily calories consumed by a similar amount, net weight loss from the low-fat diet after two years was only 6.5 lbs. (2.9 kg) compared to 10 lbs. (4.4 kg) on the Mediterranean diet, and 10.3 lbs. (4.7 kg) on the low-carbohydrate diet. "These weight reduction rates are comparable to results from physician-prescribed weight loss medications," explains Dr. Iris Shai, the lead researcher.

The Mediterranean diet has more fiber and probably a lower glycemic index than a typical low fat diet that does not take into consideration the types of carbos. When glucose enters the blood it causes insulin release to transport it out of the blood and into cells. How the body responds to that insulin and sugar probably helps to increase weight and push one's blood lipid profile in an unhealthy direction. Cutting carbohydrates does the most to improve blood lipids.

The low-fat diet reduced the total cholesterol to HDL ratio by only 12 percent, while the low-carbohydrate diet improved the same ratio by 20 percent. Lipids improved the most in the low-carbohydrate, with a 20% increase in the HDL ("good") cholesterol and, 14% decrease in triglycerides. In all three diets, inflammatory and liver function biomarkers was equally improved. However, among diabetic participants, the standard low-fat diet actually increased the fasting glucose levels by 12mg/dL, while the Mediterranean diet induced a decrease in fasting glucose levels by 33mg/dL.

Shift toward eating more monounsaturated fats (olive oil) and fish along with veggies and nuts. Cut back on the grains - especially the higher glycemic index refined grains. Check out this online searchable database on glycemic index of hundreds of foods.

One of the steps I've taken in the direction of a higher protein diet is to cook 20 lb turkeys and eat turkey every day. It is lower in fat than most red meats and lasts at least a couple of weeks afterward in a fridge kept just at the freezing point.

Update: Some are suspicious of this study because of where the funding came from.

The study was funded by a foundation established by Robert Atkins, of Atkins Diet fame. Though the Atkins Diet has a popular reputation as a meat-heavy, bacon-lover’s dream, those in the study who were assigned to the low-carb plan were counseled to favor vegetarian sources of fat and protein.

I think the study should be considered on its merits.

Dean Ornish says these results contradict the results of research he has done.

My colleagues and I at the nonprofit Preventive Medicine Research Institute and the University of California, San Francisco, have studied for more than three decades the effects of diets much lower in fat (10 percent) than the one used in NEJM study as well as lower in refined carbohydrates and higher in fruits, vegetables, whole grains, legumes and soy products.

We reported in a randomized, controlled clinical trial published in the Journal of the American Medical Association a 24-pound weight loss after one year and 13-pound average weight loss after five years in a group of men and women, much more than the 9.7 to 10.3 pounds lost in the new NEJM study.  These findings were replicated in larger demonstration projects as well.

Ornish makes the important point that some evidence links higher fat diets to prostate cancer. But at least one study found saturated fat was the source of risk for progression of prostate cancer. Ornish might be painting with too broad a brush and the monounsaturated and polyunsaturated fats might provide net benefits. One study found that polyunsaturated fats are not associated with increased risk of advanced prostate cancer.

While the Atkins Foundation funded this study and the low-carb were counseled to eat a lot of protein the participants were encouraged to eat plant protein rather than animal protein. Well, it is hard to eat a lot of plant protein.

But according to the report in The New England Journal of Medicine, the low-carb dieters in the study “were counseled to choose vegetarian sources of fat and protein.'’ Although saturated fat was not specifically restricted, the dieters were told that “moderation” was recommended.

So the dieters in this study ate less saturated fats and probably less protein than full-on Atkins dieters.

We know some foods are good. Eat lots of vegetables. That's the hardest advice of all for most to follow. Eat whole fruits. When you eat meat choose leaner meats. Eat fish. Eat beans and lower glycemic index rices rather than breads.

Share |      Randall Parker, 2008 July 16 10:13 PM  Aging Diet Weight Studies


Comments
Brock said at July 17, 2008 10:26 AM:

Dog bites man, to anyone who's actually been reading the research (not the government's politically driven recommendations).

It's more than just weight loss. A low-insulin (fructose is your only sugar), high-fat diet means you're always in ketogenesis and have low blood sugar (but high senstivity), so you live without the headaches, hunger pangs and light-headedness experienced by high-carbers when they go without a meal. This means that your metabolism and gene regulation respond to exercise much more vigorously and produce a lot less oxidative free radicals. Plus, no diabetes or other metabolic syndromes. It's really just a healthier way to live in every respect.

Brock said at July 17, 2008 11:42 AM:

Andrew - good link. I was wracking my brain for that guy's name when I was writing my previous post.

Andrew Berman said at July 17, 2008 2:41 PM:

Thanks. There's a longer one somewhere on the Berkeley website, but it requires special software. I got about halfway through Taube's book before I gave it to someone who really needs it, and she promptly ignored it. But the half I read was enough to motivate me. I'm much healthier and significantly thinner than I was before I read it.

Another interesting website is http://www.arthurdevany.com/ . 70+ year old econ professor from Berkeley who is into Evolutionary Fitness and has the body of a buff 30 year old.

Bill Quick said at July 17, 2008 3:41 PM:

What I find interesting is that most of those I've seen blogging this study are saying, "Gee, look how great the Mediterranean Diet is! For some reason they seem to not notice that it is the low-carb diet that brings the best results. Furthere, nobody seems to further notice that of the three diets, only "The low-carb dieters had no caloric intake restrictions." In other words, the low-carbers were eating ad libitem.

I'd certainly be interested to see the research definition of "low-carb" in this study, by the way. Of prime importance: was the carb level cutoff low enough to induce ketogenesis? If not, Gary Taubes' theories aren't really coming fully into play here.

I have personally been on a ketogenic diet for about 4 1/2 months, and I have lost considerably more than ten pounds - with improvements in my blood pressure and lipid counts, and with no major hunger pangs due to the ad libitem nature of my eating patterns - in other words, I eat when I'm hungry, and I eat until I no longer feel hungry.

Brian said at July 17, 2008 4:48 PM:

Amazing, considering that some in the medical establishment voiced concerns with even researching Atkins style diets for fear of harming the participents.

Andrew Berman said at July 17, 2008 6:14 PM:

Here's the kicker: In the study, there was absolutely NO CONTROL OVER BREAKFAST AND DINNER. In other words, even just changing one meal a day (albeit the major meal) was enough to have the participants lose weight in the lo carb diet.

Wolf-Dog said at July 17, 2008 8:36 PM:

This web site says that fructose consumption can actually cause insulin resistance and many problems:
http://lowcarbdiets.about.com/od/nutrition/a/fructosedangers.htm

Gyan said at July 17, 2008 9:31 PM:

It is actually polyunsaturated fats (PUFA) that could be promotors of cancer. The saturated fats are unscientifically blamed by mainstream Nutrition Science.

Brock said at July 18, 2008 6:47 AM:

Wolf-Dog, if your only source of fructose is the naturally occurring stuff in fruits it's near impossible to eat too much. You'll get sick to your stomach first. The problem sets in only when you're using refined fructose as a sweetener in all your beverages. I would think that it should be common sense by now that whenever you refine sugar and increase consumption of it tenfold, you're gonna have problems.

Echoing Bill Quick, I'm been sticking to a ketogenic diet for only the last two weeks and I've already lost 6 lbs. Most of it from the belly too, if my measurements mean anything.

Todd29 said at May 24, 2009 6:14 AM:

Diets and diet aids do not help anyone. The only way to successfully lose weight and get the body that you want is by using the right information. This information can be found in the book Lose Weight Using Four Easy Steps which can be ordered through the website www,bbotw.com Everyone who has gotten a copy of this book is now healthier.

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