Healthy Carbs, Fats for Weight Loss
Study: Low-Glycemic Dieters Have Higher Metabolisms, Feel Fuller
Nov. 23, 2004 -- One of the pitfalls of dieting is that it decreases your metabolism, making it harder to burn calories. But focusing on foods that minimally affect blood sugar may be key to keeping your metabolism revved up.
A new study shows that dieters who decreased calories while concentrating on healthy fats and carbohydrates had higher metabolisms after 10 weeks of dieting. They also reported less hunger than dieters taking in the same number of calories who ate only low-fat foods.
The two groups lost similar amounts of weight. But the findings offer early evidence that eating a so-called low-glycemic diet may overcome the body's natural tendency to slow metabolism when calories are restricted. A low-glycemic diet emphasizes healthy fats and carbohydrates.
The findings are reported in the Nov. 24 issue of the Journal of the American Medical Association.
"Almost anyone can lose weight in the short term -- very few keep it off in the long term," researcher David S. Ludwig, MD, PhD, says. "That has given rise to the notion that the body has a 'setpoint' and that when you diet internal mechanisms work to restore your weight to that setpoint. A low-glycemic-load diet may work better with these internal biological responses to create the greatest likelihood of long-term weight loss."
No Bad Food Groups
The low-glycemic diet is now widely recommended for people who are at high risk for developing type 2 diabetes. Several very popular commercial weight loss plans, including the South Beach diet and Sugar Busters, are based on it.
Instead of banning whole food groups, the diet restricts carbohydrates that are rapidly digested and spike blood sugar and insulin levels. Carbohydrates, such as refined sugar, white bread, white rice, potatoes, fruit juices, and many commercial breakfast cereals are restricted on the diet. These carbohydrates are more likely to leave you feeling hungry shortly after eating.
Whole grains, fruits, vegetables, nuts, and legumes are encouraged in a low-glycemic diet. These foods typically leave you feeling full longer.
The newly published study involved 46 overweight or obese adults who reduced calories while eating either a low-fat or low-glycemic index diet. Both diets provided approximately 1,500 calories a day and were designed to produce a 10% weight loss within six to 10 weeks.
A typical breakfast for the low-fat dieters might include instant oatmeal with skim milk and raisins. Steel-cut oats with blueberries and 2% milk would be substituted for the low-glycemic-load dieters.
Thirty-nine of the dieters lost 10% of their body weight during the study. Resting metabolism of low-glycemic load dieters slowed at about half the rate of low-fat dieters. The low-glycemic group burned about 80 calories more per day than their low-fat counterparts.
The low-glycemic dieters also reported having less hunger. They also had greater improvements in risk factors associated with diabetes and heart disease, including blood pressure, triglyceride levels, and chronic inflammation.