Israeli flag
Remember Shai et al’s 2008 DIRECT study that compared weight loss over two years on either a low-carb, low-fat, or Mediterranean diet? I reviewed it at length in 2008.
The same Isreali researchers now report the results of an additional four years of follow-up. Do you know of any other weight loss study over that length of time? I don’t.
Of the 322 original study participants, 259 were available for follow-up for an additional four years. Of these, 67% told researchers they had continued their originally assigned diet.
Over six years, the weight loss was as follows:
- 0.6 kg (about a pound) in the low-fat group
- 1.7 kg (almost 4 pounds) in the low-carb cohort
- 3.1 kg (almost 7 pounds) in the Mediterranean group
The difference between the low-carb and Mediterranean groups was not statistically significant.
Almost all the original study participants (86%) were men, so it’s debatable whether these results apply to women. I bet they do. I assume most of the participants were Israeli, so you can also debate whether results apply to other nationalities or ethnicities.
Bottom Line
For long-term weight management, Mediterranean and low-carb diets appear to be more effective than traditional low-fat, calorie-restricted dieting.
Beth Mazur at her Weight Maven blog has some worthwhile comments about the study.
Incidentally, my Advanced Mediterranean Diet (2nd Edition) book features both a traditional Mediterranean diet and the world’s first low-carb Mediterranean diet.
Diabetic Mediterranean Diet 
Dr. Parker, why is the 3.1 kg loss by the Mediterranean group over the 1.7 kg loss in the low carb group considered statistically insignificant? The difference between the two seems significant enough; perhaps the Mediterranean group was much smaller in participants.
I’ve long thought, just based on personal experience, that a low carb or Mediterranean diet is much easier to stick to due to better palatability (assuming any diet, including low fat diets, would eschew sugar!) That’s offset by our reliance on processed food, so preparing low carb meals is slightly harder. But taste? Give me a serving of eggs scrambled in butter and three strips of bacon over oatmeal with skim milk any day.
Hi, Frank.
I bet your are right that the sample size was not large enough to reach a p value 0.05 or less.
Thanks for using “eschew” – it’s underutilized.
-Steve