High Protein, Extra Exercise Combo Produces 
Dramatic Fat Loss

by Caroline J. Cederquist, MD

If you’re getting ready to roll out the old standards for your upcoming summer weight loss resolutions, here’s a little new information that might make at least a couple of those a little more effective. 

A new study from the University of Illinois shows that exercise is much more effective in weight loss when coupled with a high-protein diet.

There’s actually an extra bonus effect of using the two in combination, according to Donald Layman, the professor of food science and nutrition who conducted this latest study. 

“The two work together to correct body composition,” Layman said. “Dieters lose more weight and they lose fat, not muscle.”

When we first undertake a weight loss effort, most of us don’t really care how it’s going, as long as it goes. When we see that number on the scale change, we’re just happy it’s going down. But many diets get those initial dramatic changes through an unfortunate loss of lean muscle mass. 

That’s what happened with the subjects in Layman’s study, which ultimately showed that sticking to a diet as prescribed by the USDA’s Food Guide Pyramid actually reduced the effectiveness of exercise and caused lean tissue loss. 

This is how he determined that surprising fact. The subjects in his four-month study were divided into two dietary groups and two exercise groups. The first dietary group adhered to a low-calorie diet based on the USDA Food Guide Pyramid. The second dietary group adhered to a diet with the same calorie content, but with high carbohydrate foods like breads, pastas and potatoes replaced by high-quality proteins, like meats, eggs, nuts and dairy foods. 

Each of the two dietary groups was further divided into two exercise sub-groups, with one group adding a light walking regimen of two to three times a week to their lives, for up to 100 minutes of added exercise. 

The other sub-group was required to participate in five 30-minute walking sessions and two 30-minute weight-training sessions per week. 

Over the four months, both exercise programs helped overall weight loss. But in the high-protein group, those participants lost more weight, and almost all their weight loss was from fat not from lean muscle tissue, as is often the case.

Because the protein in lean muscle is easier to metabolize, when our bodies need more fuel (like when we’re exercising), they go for the easier target first; our muscles. 

In fact, in this study, for the high-carb/high exercise participants, up to 30% of their weight loss was from lean muscle tissue. 

If we’re losing muscle mass, we’re increasing the risk that any later excess caloric intake is going to end up converted to fat. And that’s what was happening for folks on the higher-carb Food Guide Pyramid diets. They lost weight, but also lost muscle mass. 

The protein-rich diet was high in the amino acid leucine, which works with your body’s insulin to increase synthesis of protein. That extra protein becomes available for fuel, again, helping to prevent the use of the protein in your muscles, and the subsequent muscle loss that is so common in weight loss efforts. Together with the diet’s low-carbohydrate availability, this forces the body to turn to its fat stores for the fuel it needed during that exercise. 

Now, the subjects on the high-protein diet, low-exercise diet, also lost weight, and more of their loss was from fat, compared to the high-carb exercisers. But when the scientists did all the mathematical extrapolations and comparisons, the high-protein/high exercise combo was dramatically more effective than expected.

There was something else they found in this study that really deserves some extra exploration for its own sake. It has long been an article of faith that you can’t spot reduce, because fat distribution is largely genetic and we pile it on and strip it off according to our bodies’ idiosyncratic genetic tendencies. Nobody has ever found a way to lose just thigh fat, for instance, and not, say, the facial fat that can give us that young, rosy-cheeked look. But recent research has shown that fat is not just a passive fuel storage tissue that we tote around in varied shapes. Some kinds of fat produce certain hormones that actually make us more likely to gain more weight. People who have that “apple” body shape, have more of this hormonally active fat packed into their abdomens around their organs. They tend to have higher triglyceride levels, have greater likelihood of developing insulin resistance and deadly illnesses like heart disease and diabetes. 

But the high-protein/high exercise diet seemed to be particularly good for reducing fat in the midsection and reducing the percentage of the hormonally active fat tissue. 

For most of us that are looking forward to our summer vacations, and spending time outdoors, we can use this combination of diet and exercise to produce good results. Enjoy the summer.

Caroline J. Cederquist, M.D. is a board certified Family Physician and Bariatric Physicians (the medical specialty of weight management). She specializes in lifetime weight management at the Cederquist Medical Wellness Center. Visit www.diettoyourdoor.com or www.drcederquist.com or call 800-431-1579.