Before I answer this question, let’s look to popular diet books for insight. Gary Taubes, journalist and author of Why We Get Fat—And What to Do About It, contends that obesity researchers have it all wrong, there is no evidence that diets work, no evidence that counting calories is an effective weight loss strategy, and no evidence that exercise can help you lose weight. Ironically, his litany against diets is a build-up to introducing his own diet plan (insert cash register noise), which is the wow-I’ve-never-heard-of-it, low carbohydrate diet. Oh but it’s different than previous versions, he contends that Atkins didn’t get the science right, and he then proceeds to correct the science, utilizing his background in journalism, physics, and aerospace engineering. What do those have to do with the science of weight loss? Don’t ask me, I’m an obesity researcher. Ok, so Taubes puts one vote for in for low carb diets, at least his version, which, by the way, has never been tested in a randomized trial.
In the other corner, we have Tim Ferriss, 33 year old entrepreneur and motivational speaker, who cracks open the science of obesity wielding an East Asian studies degree from Princeton and his own personal experience as a young skinny guy. His New York Times Bestseller is entitled, The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman. Sounds like an exhausting 4 hours. Plus I’m a working mom, Tim, I am already superhuman. The diet put forth is the also-not-so-novel low carbohydrates diet. Add on a few other bells and whistles (like weekly binges, ice baths, and fat burning cottage cheese) and you have his unique version, also never specifically tested in a controlled trial. Alas, that is two votes for low-carb diets.
Suzanne Somers, Sexy Forever: How to Fight Fat After Forty, is our other current bestseller. I do not know Suzanne’s training background but boy was I a fan of Three’s Company back in the day. Suzanne shares her diet secrets among which include organic food and low glycemic load foods, which involves eliminating simple carbs. That makes 3 out of 3 votes for low-carb diets.
According to mass media, low-carb diets are the most effective weight loss approach. However, when compared to other types of diets in controlled trials, do they do better? The answer is a resounding no. Several trials and reviews of trials have concluded that low-carb diets are no more or less effective than low-fat diets at weight loss. In fact, the majority of head-to-head diet studies result in a draw no matter which diets are tested. Most notably is a study by Dansinger and colleagues published in the Journal of the American Medical Association in 2005. This study compared Atkins (low carb), Zone (low carb), Weight Watchers (low fat), and Ornish (low fat) diets and found no differences between diets in weight loss. The strongest predictor of weight loss was adherence to the diet, regardless of which diet it was. In 2006, the Archives of Internal Medicine published a review of 5 trials that compared low-fat to low-carb diets and the conclusion was that weight loss was no different in these trials. More recently, in 2010, Foster and colleagues published randomized trial findings in Annals of Internal Medicine that showed no weight loss differences in low-carb versus low-fat diets at 2 years. Wycherly and colleagues also published a randomized trial in 2010 in the Journal of Internal Medicine that showed no difference in weight loss between low-carb and low-fat diets. In my search of this literature, I could not find a single trial that showed a weight loss advantage of one or the other of these diets.
Let’s revisit our original question: what is the BEST weight loss diet? None? No, the answer is the diet you can stick to for the long haul. The diet you want to marry, until death do you part. Remember the Dansinger study found that the strongest predictor of success is sticking to it? What this means is that you have to pick something that you can stick to and not just for a few weeks or months, forever. Short-term adherence means short-term weight loss. If you love steak, cheese, and eggs, and you can live without the bread basket, then a low-carb diet will be a good fit. If you love carbs and could live with less meat and cheese, then a low-fat diet makes the most sense for you. Unfortunately, people who love carbs feel like they need to give up carbs to lose weight. Not so! Your weight loss diet should be one that reflects your tastes and preferences. The diet you will stick to best is the one that is the most similar to your current diet.
Try this. Write down what you eat for one week, figure out the calories, carbs, fat, and protein, and then calculate the percentage of your calories that come from carbohydrates, fat, and protein. This will give you an idea of your tastes and preferences. A balanced diet is 30% fat, 30% protein, 40% carbs. If your numbers are higher on any of these, that indicates your preference. For example, if you are 35% fat, 35% protein, and 30% carbs, you are a good candidate for low-carb diet. When I look at mine I see that I eat a slightly higher percentage of calories from carbohydrates. A low-carb diet would be hard for me to follow, I would have to give too much up, not to mention consuming foods that I do not enjoy (did I mention I lasted 1 day on Atkins, but have been eating low fat for 20 years?). A diet mismatch will not work in the long run. This does not mean that a high carb eater does not need to cut back on carbs, in fact she/he probably does to some extent, but a low-carb diet is going to be too extreme a reduction in carbs to feel comfortable. You will be going too much against the grain (pun intended). The more extreme a step you take from your norm, the harder it will be in the long run. In fact, make the fewest changes to your current diet that are necessary to achieve weight loss.
The diet books will come and go. The bottom line is to take what the aerospace engineers, Asian lit majors, and anyone else yielding a pen says with a grain of salt. What works for you, really is what is going to work for YOU. Only you can know what this is.
Dansinger, M.L.,et al. (2005). Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction: A Randomized Trial. Journal of the American Medical Association, 293(1), 43-53.
Wycherly et al (2010). Long-term effects of weight loss with a very low carbohydrate and low fat diet on vascular function in overweight in obese patients, Journal of Internal Medicine, 267 (5), 452-461.
Foster et al (2010). Weight and metabolic outcomes after 2 years on a low-carbohydrate versus low-fat diet: A randomized trial. Annals of Internal Medicine, 153(3), 147-157.
Nordmann et al (2006). Effects of low-carbohydrate versus low-fat diets on weight loss and cardiovascular risk factors. Archives of Internal Medicine, 166, 285-293.Share on Facebook