This blog tracks updates to the Blood Sugar 101 Web site.

Tuesday, August 3, 2010

Long Term Low Carb Diet Better for Health than Low Fat in Randomized Trial

Page Changed: Studies Proving the Safety and Efficacy of the Low Carb Diet

A 2010 Study Finds Low Carb Diet Beats Low Fat at Improving Health Long Term

An NIH-funded study published in 2010 compared an Atkins type low carb diet to a low fat/low calorie diet over a 2 year period. This study was distinguished from earlier studies in that participants were given ongoing support to help them stay on track.

Both groups lost the same amount of weight over the two years on average. However, as stated in the results:
During the first 6 months, the low-carbohydrate diet group had greater reductions in diastolic blood pressure, triglyceride levels, and very-low-density lipoprotein cholesterol levels, lesser reductions in low-density lipoprotein cholesterol levels, and more adverse symptoms than did the low-fat diet group. The low-carbohydrate diet group had greater increases in high-density lipoprotein cholesterol levels at all time points, approximating a 23% increase at 2 years.
Though this study excluded people with diabetes, the finding confirms what people with diabetes have been reporting, anecdotally for years and removes any basis on which doctors and nutritionists can rest their oft repeated claim that the low carb diet is dangerous.

Weight and Metabolic Outcomes After 2 Years on a Low-Carbohydrate Versus Low-Fat Diet: A Randomized Trial Gary D. Foster et al. Annals of Internal Medicinevol. 153 no. 3 147-157 Aug 3, 2010.


Anna said...

I suspect a lot of folks will be talking/blogging about this study. Dr. Eades has mentioned it today in a comment on his blog.

Another blogger also mentions the interesting issue of "Intention to Treat" with regard to this (and other diet studies):

Jenny said...

The "intention to treat" blog post raises an interesting question. Looking at the results of those who stuck to the diets while ignoring those who dropped out would be interesting.

But because in ever diet study so many people DO drop out even those who are given ongoing support, I think a case can be made that there are problems with all diets that limit their effectiveness and that much more study needs to be devoted to learning how to solve the problems which make them drop out.

Many of them are physiological, not psychological, though the tendency is still to blame people for failing on diets, rather than to see their decision to quit as a rational response to serious problems they've encountered.

It is the VERY high drop out rate of the extreme kind of low carb diet Dr. Eades promotes that leads me NOT to recommend it to people with diabetes who will suffer grievous harm if they go back to eating very high carb diets.

A moderately low carb diet between 80-100 g can be much, much easier to stick to and provides dramatic blood sugar improvements for many people with Type 2.

If it doesn't, it is time to add safe effective drugs rather than getting into a will-power based struggle to eat in a way that many people find extremley hard to stick to.

The goal with diabetes is to achieve and sustain normal blood sugar and avoid complications, and the best diet is the one that the person can stick to for the longest period of time while achieving that goal.

Anna said...

In case readers miss the link within the link I mentioned in my earlier comment: here is a direct link to a very good 2009 full text commentary by Richard Feinman on Intention to Treat in the journal Nutrition and Metabolism:

water said...

What were some of the adverse effects from adopting a low carb diet? gluten intolerance?

Jenny said...

Gluten intolerance isn't caused by cutting out wheat.

I don't have access to the full text but my guess is it would be things like headache or dizziness which are common early on in very low carb diets like the one they specified.

water said...

I think I did not express my thought very clearly. What I meant was that some food intolerances aren't discovered until a diet change. My spouse had mild and occasional heartburn before low carb, after changing his diet (because of high FBG), his digestive issues were much worse, until we realized that gluten intolerance was the issue.

It would be interesting what they consider a side effect.