Written by Team MD


1) High Protein Intake Maintains Metabolic Rate During Low-Calorie Diets

 Losing weight and maintaining lost weight is difficult because metabolic rate (i.e., calorie burning) gradually slows, which makes it difficult to sustain a negative caloric balance. Researchers from Maastricht University in the Netherlands found that consuming a high-protein, low-calorie diet maintained metabolic rate better than a high-carbohydrate, low-protein and low-calorie diet. During the early phases of the weight-loss program, the high-protein diet prevented hunger but this disappeared during the later phases of the 12-week experiment. Consuming high amounts of protein during dieting and weight maintenance will help maintain metabolic rate and increase the chances for successful weight loss. (Clinical Nutrition, published a online November 8, 2014)

2) Low-Glycemic Index Foods Rev Up Energy Levels

Consuming low-glycemic index foods may help boost energy levels and maintain bodyweight. The glycemic index is a measure of how fast a food increases blood sugar. Simple, refined carbs increase blood sugar quickly followed by rapid decreases, which can have a “yo-yo” effect on energy levels— according to the Harvard Women’s Health Watch. Consuming complex carbs results in a slower and more sustained increase in blood sugar, which helps maintain energy levels. Examples of low-glycemic index foods include 100 percent stone-ground whole wheat, oatmeal, oat bran, muesli, pasta, converted rice, corn, beans, apples, oranges, melons and yams. High-glycemic index foods include white bread, bagels, corn flakes, instant oatmeal, white rice, popcorn and saltine crackers. High-glycemic index foods, however, are effective fuels during and immediately after exercise because they provide sugar quickly to fuel exercise and replenish depleted carbohydrates. (Harvard Women’s Health Letter, December 2014)

3) Best Way to Lose Weight: Diet, Exercise or Diet + Exercise?

Want to lose 20 pounds? Should you go on a starvation diet, run 20 miles a week or reduce calorie intake and exercise moderately? Richard Washburn and co-workers from the University of Kansas Medical Center in Kansas City performed a detailed literature review of studies published between 1990 and 2013. Caloric restriction caused the greatest weight loss. Dieting was more effective than aerobics plus a normal diet or diet plus exercise. However, most studies included only about 30 minutes of exercise. In 2005, the U.S. Department of Agriculture guidelines recommended one to one-and-a-half hours of aerobic exercise per day for people wanting to lose weight or maintain lost weight. This was based on doubly labeled water studies that precisely measured the minimum amount of exercise necessary to lose weight. Few people are willing to do that much exercise. In the long run, people lost the most weight and maintained lost weight best when they combined diet and exercise. (PLOS ONE 9(10): e109849, 2014)

4) Five Reasons You Gain Weight

Weight and fat are national obsessions because more than two-thirds of Americans are overweight or obese. Most people have misperceptions about weight gain. Common beliefs include low metabolism, high digestion of food, damaged metabolism due to chronic dieting, eating one or two large meals per day instead of many small meals, and consuming too many carbs. All of these are urban legends and are not true. Claude Bouchard from the Pennington Biomedical Research Center in Louisiana has identified five factors linked to weight gain: 1) low muscle mass, which reduces metabolic rate; 2) low fitness, which decreases the capacity to expend calories through physical activity; 3) low testosterone, which is linked to the capacity to build muscle; 4) insensitivity to the hormone leptin, which helps control appetite and metabolic rate and 5) inability to directly burn dietary fat as fuel, which results in greater fat storage. No single factor is responsible for weight gain. The complexity of body fat control helps explain why it is so difficult to lose weight and keep it off. (New Scientist, November 15, 2014)

5) Ketogenic Diets Suppress Appetite

The brain uses mainly glucose (sugar) for fuel but it can also use ketones and lactate. During low-calorie dieting, the body produces ketones to supply fuels to the brain. The liver produces ketones that come from fatty acids released during fat breakdown that occurs due to low calorie intake. A literature review by researchers from the University of Sydney in Australia concluded that ketones produced during very low-calorie diets suppress appetite slightly. Ketogenic diets (i.e., low-calorie diets that result in ketone production) decrease appetite and increase the feeling of fullness even during severe caloric restriction. Normally, appetite increases during low-calorie dieting. (Obesity Reviews, published online November 17, 2014)