Protein Is the Darling of the Dieting Set -- For Now
The researchers wanted to determine if a high-protein weight-loss diet (30% of calories from protein), compared to a lower-protein weight-loss diet (15% of calories from protein), was more effective in reducing the components of insulin resistance syndrome. Even though there was no difference in the amount of weight loss between the two groups after 12 weeks, the results show improved insulin sensitivity with a high-protein diet -- and the numbers were most significant in men.
Despite the promising results, Clinton doesn't think clinicians should encourage their patients who have insulin resistance syndrome to embark on high-protein diets. "We need to wait for good data to show that's the way we should go," he tells WebMD. "At this point, we aren't sure about the long-term problems with [protein] diets. I know that high-protein diets are hard to achieve over the long term. ... So while it's possible our theory might be right, we certainly want to confirm it in a much larger study."
Others remain convinced that it's the calories that count. "Generally, what we do know is that it's calories that count in weight management, not necessarily hormonal responses to energy sources," Jennifer Nelson, MS, RD, tells WebMD. Nelson is the director of clinical dietetics at the Mayo Clinic in Rochester, Minn. "Because there is so little research on this, we can't substantiate those claims. Those claims are unverified."
Somewhat similar to the Zone diet is the so-called "Mayo Clinic" diet. But dieters beware!
"Don't be fooled. This diet has been attributed to the Mayo Clinic since the 1940s," says Nelson. "We started receiving calls in the '40s about a diet that emphasizes a lot of protein, very limited, if any, starch, very few fruits, and very limited vegetables. I think the only fruit it allows is grapefruit because it supposedly 'burns' body fat. To the best of our knowledge, it never originated at the Mayo Clinic and we do not endorse its use.
"I think that one of the reasons these types of diets are popular is that they initially do result in immediate weight loss. When you eat a high-protein diet, you have a tendency to lose more water weight than body fat per se, and so you get a more immediate response," says Nelson. "But are you truly losing the type of weight you need to lose?"
"Weight management should not be short-term; it needs to be a lifelong commitment. If you go at it short-term you are going to struggle gaining and losing the same pounds over and over again," says Nelson. "And when you take the longer view of weight management, a well-balanced diet that provides all of the necessary nutrients in the amounts that are needed ends up being very important."