This study was a meta-analysis of name-brand diet interventions on weight loss.
Initially, the researchers cast a broad net to identify potential studies to include in the analysis. They tried to identify any study of overweight or obese adults who were treated with a specifically named diet or a diet that was equivalent to a named diet, even if that name was not explicitly mentioned. For example, a study diet could be not explicitly called “Atkins,” but would be grouped under “Atkins-like diets” if they were funded by Atkins or fit the general guidelines of the Atkins diet.
These criteria were used to search the largest databases of published research, like PubMed. The authors confirmed assigned each study as either being at low or high risk of bias using the Cochrane risk of bias tool. This tool evaluates the quality of a study’s methodology and reporting, such as sufficient reporting of all main outcomes and adequate description of blinding procedure.
Studies that included exercise or behavioral interventions were included, and those factors were later assessed to determine if they contributed to overall weight lost. Similarly, the researchers allowed studies that included some meal replacements, but the intervention could not involve any drugs or drug-like supplements, like ephedra or similar “fat burners.” The studies also had to have lasted at least six months. Many of the studies lasted longer than that. The longest study the researchers analyzed lasted 12 months.
There were 59 articles identified in total, which were based on 48 randomized controlled trials enrolling a total of 7286 individuals. These reports included 11 diets, which were roughly categorized as moderate macronutrient, low-carb, or low-fat. Control groups included participants who followed no diet and who received “usual care,” which included adaptive or variable weight management strategies, such as LEARN (Lifestyle, Exercise, Attitudes, Relationships, Nutrition: a behavior-based approach to weight loss), which can be modified based on an individual’s needs.
This study compared various diets intended for weight loss in an attempt to find the most effective one.