Adult Weight Loss Diets: Metabolic Effects and Outcomes

The global prevalence of overweight and obesity as a public health concern is well established and reflects the overall lack of success in our ability to achieve and maintain a healthy body weight. Being overweight and obese is associated with numerous comorbidities and is a risk factor for several of the leading causes of death, including cardiovascular disease, diabetes mellitus, and many types of cancer. The foundation of treatment has been diet and exercise. There are >1,000 published weight loss diets, with more appearing in the lay literature and the media on a regular basis. The sheer number of existing diet regimens would suggest that no one diet has been universally successful at inducing and maintaining weight loss. Many of these dietary programs are based on sound scientific evidence and follow contemporary principles of weight loss. Others simply eliminate 1 or more of the essential food groups or recommend consumption of 1 type of food at the expense of other foods with little to no supporting evidence. The focus of this review is on weight loss diets, specifically those with the most supporting scientific evidence and those that are most likely to succeed in achievement and maintenance of desirable body weight. The effects of weight loss diets on energy expenditure, body weight, body composition, and metabolic parameters will be evaluated. Ultimately, the best diet is the one the patient will follow and incorporate into his or her daily life for lifelong maintenance of a healthy body weight.