Importance: No retrospective cohort study has assessed the effectiveness of semaglutide at doses used in randomized clinical trials to treat obesity (ie, 1.7 and 2.4 mg).Objective: To study weight loss outcomes associated with semaglutide treatment at doses used in randomized clinical trials for patients with overweight or obesity.Design, Setting, and Participants: This cohort study, conducted at a referral center for weight management, retrospectively collected data on the use of semaglutide for adults with overweight or obesity between January 1, 2021, and March 15, 2022, with a follow-up of up to 6 months. A total of 408 patients with a body mass index (BMI) of 27 or more were prescribed weekly semaglutide subcutaneous injections for 3 months or more. Patients with a history of bariatric procedures, taking other antiobesity medications, and with an active malignant neoplasm were excluded.Exposures: Weekly 1.7-mg or 2.4-mg semaglutide subcutaneous injections for 3 to 6 months.Main Outcomes and Measures: The primary end point was the percentage of weight loss. Secondary end points were the proportion of patients achieving weight loss of 5% or more, 10% or more, 15% or more, and 20% or more after 3 and 6 months and the percentage of weight loss for patients with or without type 2 diabetes after 3 and 6 months.Results: The study included 175 patients (132 women [75.4%]; mean [SD] age, 49.3 [12.5] years; mean [SD] BMI, 41.3 [9.1]) in the analysis at 3 months and 102 patients at 6 months. The mean (SD) weight loss after 3 months was 6.7 (4.4) kg, equivalent to a mean (SD) weight loss of 5.9% (3.7%) (P < .001), and the mean (SD) weight loss after 6 months was 12.3 (6.6) kg, equivalent to a mean (SD) weight loss of 10.9% (5.8%) (P < .001 from baseline). Of the 102 patients who were followed up at 6 months, 89 (87.3%) achieved weight loss of 5% or more, 56 (54.9%) achieved weight loss of 10% or more, 24 (23.5%) achieved weight loss of 15% or more, and 8 (7.8%) achieved weight loss of 20% or more. Patients with type 2 diabetes had a lower mean (SD) percentage weight loss at 3 and 6 months compared with those without type 2 diabetes: 3.9% (3.1%) vs 6.3% (3.7%) at 3 months (P = .001) and 7.2% (6.3%) vs 11.8% (5.3%) at 6 months (P = .005).Conclusions and Relevance: The results of this cohort study suggest that weekly 1.7-mg and 2.4-mg doses of semaglutide were associated with weight loss similar to that seen in randomized clinical trials. Studies with longer periods of follow-up are needed to evaluate prolonged weight loss outcomes.

Objective: Little is known about the predictors of response to obesity interventions.Methods: In 450 participants with obesity, body composition, resting energy expenditure, satiety, satiation, eating behavior, affect, and physical activity were measured by validated studies and questionnaires. These variables were used to classify obesity phenotypes. Subsequently, in a 12‐month, pragmatic, real‐world trial performed in a weight management center, 312 patients were randomly assigned to phenotype‐guided treatment or non‐phenotype‐guided treatment with antiobesity medications: phentermine, phentermine/topiramate, bupropion/naltrexone, lorcaserin, and liraglutide. The primary outcome was weight loss at 12 months.Results: Four phenotypes of obesity were identified in 383 of 450 participants (85%): hungry brain (abnormal satiation), emotional hunger (hedonic eating), hungry gut (abnormal satiety), and slow burn (decreased metabolic rate). In 15% of participants, no phenotype was identified. Two or more phenotypes were identified in 27% of patients. In the pragmatic clinical trial, the phenotype‐guided approach was associated with 1.75‐fold greater weight loss after 12 months with mean weight loss of 15.9% compared with 9.0% in the non‐phenotype‐guided group (difference −6.9% [95% CI −9.4% to −4.5%], P < 0.001), and the proportion of patients who lost >10% at 12 months was 79% in the phenotype‐guided group compared with 34% with non‐phenotype‐guided treatment group.Conclusions: Biological and behavioral phenotypes elucidate human obesity heterogeneity and can be targeted pharmacologically to enhance weight loss.

Food intake regulation in humans is a complex process controlled by the dynamic interaction of homeostatic and hedonic systems. Homeostatic regulation is controlled by appetitive signals from the gut, adipose tissue, and the vagus nerve, while conscious and unconscious reward processes orchestrate hedonic regulation. On the one hand, sight, smell, taste, and texture perception deliver potent food-related feedback to the central nervous system (CNS) and influence brain areas related to food reward. On the other hand, macronutrient composition stimulates the release of appetite signals from the gut, which are translated in the CNS into unconscious reward processes. This multi-level regulation process of food intake shapes and regulates human ingestive behavior. Identifying the interface between hormones, neurotransmitters, and brain areas is critical to advance our understanding of conditions like obesity and develop better therapeutical interventions. Neuroimaging studies allow us to take a glance into the central nervous system (CNS) while these processes take place. This review focuses on the available neuroimaging evidence to describe this interaction between the homeostatic and hedonic components in human food intake regulation.