It is known that diet and lifestyle behaviors affect weight loss and maintenance of healthy weight. This study followed large populations to investigate the effects of changes in diet and behavior on weight maintenance and weight gain over a long period of time. Results showed that within each four-year period, most of the participants gained an average of 3.35 lbs. This four-year weight change was attributed to increased intake of potatoes, sugar-sweetened beverages, processed meats and unprocessed red meats. The increased intake of vegetables, fruits, whole grains, yogurt and nuts was found to prevent weight gain. However, lifestyle factors including poor physical activity, alcohol consumption, smoking, less or more sleep and too much television watching led to weight gain.
There is an alarming rise in rates of overweight and obese individuals in the global population. It is known that obesity is associated with problems such as diabetes, heart disease, arthritis and cancer. Diet restrictions and physical activity form the basis of weight loss programs. In most weight-related studies, obese and overweight people have been studied for short durations with intensive physical activity and dietary restrictions. Such aggressive measures show benefits over a short duration and involve only those who are at risk of obesity or are obese. It is known that weight gain occurs gradually in the general healthy population as well, and may increase by about 1 lb. per year. There have been no studies that analyze all the diet and behavioral factors that lead to long-term weight gain in a general healthy population. This study followed a large population over the years to understand the factors in diet and lifestyle that may lead to weight gain and obesity or protect from weight gain and allow for maintenance of a healthy body weight.
* This study included 120,877 American women and men who were healthy and not obese at the beginning of the study. They pulled the participants from the Nurses’ Health Study, Nurses’ Health Study II and the Health Professionals Follow-up Study.
* All the participants were placed under observation continuously from 1986 to 2006, 1991 to 2003 and 1986 to 2006.
* After every four years of the study, the participants were asked about their diet and lifestyle and were categorized by age, sex, body mass index (weight in kg over height in meters squared) etc. Trends of change and their association with the various diet and lifestyle factors were evaluated.
* The results showed that participants gained an average of 3.35 lbs. every four years.
* The most common reasons for weight gain remained food. Weight change was associated with the intake of potato chips (1.69 lbs.), potatoes (1.28 lbs.), sugar-sweetened drinks (1 lb.), red meats (0.95 lb.) and processed meats (0.93 lb.).
* On the other hand, weight change was inversely associated with the intake of vegetables (-0.22 lb.), yogurt (-0.82 lb.), nuts (-0.57 lb.), fruits (-0.49 lb.) and whole grains (-0.37 lb.).
* Physical activity led to an average loss of 1.76 lbs. while weight was gained by alcohol intake to 0.41 lb. and television watching by 0.31 lb. Smokers who quit lost weight by 5.17 lbs. in new quitters and 0.14 lb. in former smokers. Too much (more than eight hours) or too little (fewer than six hours) sleep also led to weight gain.
Authors agree that they did not take into account several factors. These include portion sizes, exact reasons for lifestyle changes, ethnicities and food-related cultural differences etc. The authors believe that the results regarding the changes were mostly self report and this comes with a degree of error due to misreporting. Further studies are warranted o evaluate these conclusions.
This study shows that weight gain may often be gradual and unintended and could be reversed by making changes in dietary and other habits. This study reveals that consumption of fruits, vegetables, nuts, whole grains, yoghurt and increase in physical activity may be effective in the prevention of weight gain. Cutting down on watching of television, alcohol, smoking, potatoes, sugar-sweetened drinks and red and processed meats could help in the prevention of weight gain. The authors suggest that there are population as well as individual strategies that can help lose weight and maintain healthy weights. These can be “most effective when particular foods and beverages are targeted for decreased (or increased) consumption.”
For More Information:
Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men
Publication Journal: The New England Journal of Medicine, June 2011
By Dariush Mozaffarian, MD; Tao Hao; Harvard School of Public Health, Boston, MA
*FYI Living Lab Reports Are Summaries of the Original Research.