Now there is the million dollar question, right? Interestingly, despite billions of health care dollars being spent on “diets”, there are not recent high level studies in the medical literature to support touting one weight loss diet highly above all the rest. In 2001, there was a scientific review of popular diets by Freedman, King, & Kennedy, that concluded “low fat, low calorie diets are the most successful in maintaining weight loss.” Note- this is in MAINTAINING weight loss, not LOSING weight. Ultimately, as should come as little or no surprise, CALORIC BALANCE is the major determinant of weight loss, regardless of the composition.
So…which diet? HIGH protein, LOW carb diets have a very high satiety effect- you are simply not as HUNGRY when you restrict calories if there is a high protein content. Several studies have demonstrated that the less hungry (more satiated) people are, the higher their compliance rate with a calorie restricted diet. This sounds rather obvious- if you are not hungry, you won’t “cheat”- BUT…remember most of us do not eat because we are hungry. We eat because we are happy, sad, mad, bored, distracted- you name it. (See related post “Break the Eat, Repent, Repeat Cycle”).
Are high protein diets safe for the kidneys? A 2012 study at the Indiana School of Medicine confirmed that low carb, high protein diets do NOT cause any harm to the kidney function in obese patients who had healthy kidneys at the start.
What about the heart? A very large study this year in Sweeden (>40,000 women) did show that women do develop an increased risk of cardiovascular disease (heart attacks & stroke) if they stay on a low carb/ high protein diet long-term. However, in the short term (at one year), low carb/high protein diets are more effective in weight loss and reducing cardiovascular disease risk.
BOTTOM LINE: Low carb/ high protein diets may help you lose weight in the short term (~ a year), but for long-term weight maintenance or continued weight loss, go for what you know to be healthy- MORE fruits & vegetables & a lean protein source.