While perusing the internet I found this study published by the New England Journal of Medicine! The study at first seemed promising as it compared low-fat, Mediterranean and low-carb diets. As I read the abstract I started getting confused.
Methods In this 2-year trial, we randomly assigned 322 moderately obese subjects (mean age, 52 years; mean body-mass index [the weight in kilograms divided by the square of the height in meters], 31; male sex, 86%) to one of three diets: low-fat, restricted-calorie; Mediterranean, restricted-calorie; or low-carbohydrate, non–restricted-calorie.
Ok - so far so good but it seemed a little off-kilter already with 86% of the participants being men. The confusing part to me after reading the two-year results (converted into pounds) were:
- The low-fat group lost 6.39 pounds
- The Mediterranean group lost 9.70 pounds
- The low-carbohydrate group lost 10.36
I am going to point out the study’s results, benifits and then the logical problems that many readers of this study might notice (at least I did). I will also speak about existing alternatives that work (I have lost 30 pounds so far since the beginning of the year). I found this Hardee’s low-carb Goldilocks spoof in honor this study’s low-carb diet winner for your perusal.
The study’s conclusions (from the abstract) was that Mediterranean and low-carb diets are good choices when considering low-fat diets. The study also notices some glycemic and metabolic benifits of these two diets when compared to the low-fat diet.
In the discussion section the writers suggested that one benefits of the low-carbohydrate diet might be for people that do not like to follow a diet (because of no caloric restrictions).
One good thing about this study is the participants were followed and cataloged often, allowing researchers to find some seemingly answers as well as other questions for other areas of study.
As I see it there are four main problems with this study that make the results suspect:
- 1500 calories for women and 1800 calories for men selected for the low-fat and Mediteraen diets
- The low-fat diet and the Mediterraen diet were about the same percentage of fat
- Low-fat diets are more normally from 10% to 20% of fat calories
- The amount of exercise was not part of the overall plan but rather calculated on an individual basis
Since the study had 86% men, I used a internet calculator to get a range of calories the average 52 year-old, 5′9″ (I think the average) man that does little to no exercise. The base caloric needs are 1548 calories. The total combined caloric needs are 1857 calories (with his little to no exercise) and his suggested calories to affect weight-loss are 1357 calories a day. You will notice that this is well under the 1800 calories a day the study allowed for both the low-fat and Mediterranean diet.
I already pointed out that a low-fat and the Mediterraen diet had about the same percentage of fat. The low-fat diet in this study was based on the American Heart Association guidelines. The problem with using 30% for a low-fat diet is do you then extrapolate that 50% fat is a medium-fat diet and 70% fat is a high-fat diet? I’m being facetious here but think about this… if low fat is as high as the Mediterraen diet… how is that low-fat? The more normal low-fat diets are as outlined in my book entitled, “Slimmer Zimmer” or this CNN story about a study cutting ovarian cancer risks with a low-fat diet (both around 20% fat).
I would have liked to have seen exercise be a big part of the variables when setting up this study as exercise can negate some of the caloric intake reduction needed to lose weight! In the example of the 5′9″, 52 year-old man that decides to do moderate exercise (as opposed to little to none), you will see the base rate increase to 1588 (calories) and the total calories used increased to 2399. This increase in activity level would allow this man to diet by eating about 1900 calories a day!
Here is what I think. This was a well intentioned study that did not take into real-life variables and therefore does not have much applicability to real-people. Think about it… normal diets that nutritionists design today can have people safely losing one to two pounds a week based on total diet and exercise. So please forgive me if I am not all that impressed with a comparison of a flawed (my opinion) study where the best two-year results are less than eleven pounds!
Now that you know my opinion of this study’s applicability to dieting, I do think this study has excellent, salient points for academic researchers. Unfortunately this study fell short of evaluating real low-fat, Mediterranean and low-carb diets that are in use today (based on the low-fat diet being off). I will admit that I do not have a lot of knowledge of the Mediterranean diet but I believe my guess to be accurate because none of the diets in this study had any real results (.015 pound lost a day or 11 pounds for two years).
Sorry this was more of an evaluation than my normal motivational posts… I was just intrigued by this study and how people might perceive it in the real world. What do you think?
That Hardee’s video? The creepiest thing I’ve ever seen. Yet strangely compelling (kinda like their food!)!
I agree - most weight-loss studies don’t seem to have any connection to the real dieting world!
I thought the video was over the top too… you know, the kind, gentle bears that we all remember protecting their home from goldilocks, reduced to a low-carb meal!
I liked your site.