Changes in the prevalence of U.S. adults using diet, exercise, pharmaceuticals and diet products for weight loss over time: Analysis of NHANES 1999–2018

To examine changes in the use of diet, exercise, and pharmacological/diet product weight loss (WL) practices over time, and differences in these trends by sex and obesity status, data from the National Health and Examination Survey (NHANES Continuous 1999–2018) was used. The prevalence of diet, exercise and use of WL drugs and products over time were examined in men and women with and without obesity in a series of cross-sectional nationally representative samples (n = 43,020). Women and those with obesity were more likely to engage in WL practices over the past year, with an increased prevalence of WL efforts over time (38.4 to 43.2%). Amongst those who engaged in WL attempts, diet-related WL was most common (87–93%), followed by exercise-related WL (47–68%), whereas use of WL drugs and products was the least common (5–21%). There were modest differences in the prevalence of diet or exercise WL over time, with some differences by sex and obesity status. Most notable was the increase in the prevalence of exercise WL practices in women with obesity, with no differences among men or women without obesity. When examining specific types of diets, there were more clear differences in the adoption of diets over time, with the use of more traditional calorie/portion/fat restriction diets becoming less prevalent, and sugar/carbohydrate restriction becoming more prevalent over time (P<0.005). Changes over time in the use of diets were, were however, similar in men and women with and without obesity. Use of pharmacotherapy/diet products tended to decline in prevalence over time but was consistently highest in women with obesity. Thus, there are differences in the types of WL strategies individuals have employed over time, with variations in their popularity of use by sex and obesity status. However, the pattern of changes over time were quite similar in men and women with and without obesity.