POUNDS LOST study

Long-Term Weight Loss—What Works? Tips from the POUNDS LOST Study

When it comes to counseling individuals about weight loss, separating fad from fact can be a never ending battle. A recent study shows heart healthy diets that reduce calorie intake—regardless of differing proportions of fat, protein, or carbohydrate—can help overweight adults achieve and maintain weight loss. The findings serve up evidence that the key to weight loss success has nothing to do with fads, and provide insight into developing successful weight-loss programs.

What was the study?

The Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) Study, funded by the National Heart, Lung, and Blood Institute, compared weight-loss diets with different compositions of macronutrients and was published in the New England Journal of Medicine, Feb 26, 2009.

• Participants were 811 overweight adults who ranged from 30 to 70 years. The group was diverse, with 38 percent men and 22 percent representing minorities.
• Individuals were randomly assigned to one of four diets that varied in macronutrient content. Diets were low or high in total fat (20 or 40 percent of calories), were average or high in protein (15 or 25 percent) and ranged from 35 to 65 percent in carbohydrate content.
• Participants were given personalized calorie (kcal) goals that ranged from 1,200 to 2,400 kcal per day (a deficit of 750 kcal/day based on the person’s resting energy expenditure and activity level).
• All diets were heart healthy, including at least 20 grams of dietary fiber per day, 8 percent or less of saturated fat, and 150 mg or less of cholesterol per 1,000 kcal.
• Participants were asked to do 90 minutes per week of moderate physical activity.
• Group diet counseling sessions were held at least twice per month throughout the two years of the study, and individual sessions were held every eight weeks.

What did the study find?

• The four diets were equally successful in promoting clinically meaningful weight loss.
• Participants lost an average of 13 pounds at 6 months (7 percent of their initial weight). After 12 months they began to regain weight.
• Among the 80 percent of participants who completed the 2-year study, the average weight lost was 9 pounds and 15 percent had a reduction of at least 10 percent of their initial body weight.
• Participants reduced their waistlines by 1 to 3 inches by the end of the study.
• Craving, fullness, hunger, diet satisfaction, and attendance at group sessions were similar across the four diets. 
• The diets improved lipid-related risk factors and fasting insulin levels.
• Attendance at group sessions strongly predicted weight loss at 2 years. The researchers believe this is because attendance indicates the participants’ commitment to achieving weight loss.

What are the take-home messages?

• Heart healthy diets that lower calorie intake can help overweight and obese adults achieve and maintain weight loss and reduce their heart disease risk.
• The proportions of fat, protein, or carbohydrate are not crucial. Given a specific regimen, participants will tend to revert to their customary macronutrient intake over time, but can still maintain weight loss if calories are reduced. 
• Behavioral factors, rather than macronutrient proportions, play a key role in weight loss. Attendance at nutritional counseling sessions that is continued after initial weight loss has occurred can be effective in minimizing weight regain.
• In summary, heart-healthy diets that are tailored to individuals based on their personal and cultural preferences, and that are taught with enthusiasm and persistence, have the best chance for long-term success.

Where can I learn more about the study?

• Heart-Healthy, Reduced-Calorie Diets Promote Long-term Weight Loss. (press release) http://public.nhlbi.nih.gov/newsroom/home/GetPressRelease.aspx?id=2624
• Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. Sacks, F. M., et al., The New England Journal of Medicine, 360:859-73, 2009.
  http://content.nejm.org/cgi/content/full/360/9/859

Where can I get more information about diets and weight loss?

• Aim for a Health Weight Resources
  http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/index.htm
• NHLBI  Menu Planner
  http://hp2010.nhlbihin.net/menuplanner/menu.cgi
• NHLBI Diseases and Conditions Index 
  http://www.nhlbi.nih.gov/health/dci/Diseases/obe/obe_whatare.html

Additional Information on the POUNDS LOST study

• The percentages of macronutrients in the four diets were:
  • 20% fat, 15% protein, 65% carbohydrate
  • 20% fat, 25% protein, 55% carbohydrate
  • 40% fat, 15% protein, 45% carbohydrate
  • 40% fat, 25% protein, 35% carbohydrate
• The improved risk factors included reduced levels of triglycerides and LDL-cholesterol, increased HDL-cholesterol, lowered blood pressure, and lower fasting insulin levels.
• The study was conducted from October 2004 through December 2007 at 2 sites: the Harvard School of Public Health and Brigham and Women’s Hospital, Boston; and the Pennington Biomedical Research Center of the Louisiana State University System, Baton Rouge.