A new study from the Harvard T.H. Chan School of Public Health suggests that combining GLP-1 weight-loss medication with tailored nutrition and physical activity intervention is crucial to mitigate side effects, preserve muscle, and prevent nutritional deficiencies. The growing use of GLP-1 and dual receptor agonists has led to widespread weight loss, often without changes in diet or exercise.
Previous research has shown that these agents suppress appetite and slow gastric emptying, raising concerns about adequate protein, micronutrient, and fluid intake. Loss of lean mass has also been documented across all weight-loss interventions, with 25% to 40% of weight lost attributed to muscle tissue.
The study’s authors provide practical clinical strategies to manage side effects and support nutritional and muscular preservation for patients using GLP-1 RA medications. Recommendations include monthly weight monitoring during medication titration and quarterly thereafter. Low responders may require extended titration, evaluation for missed doses, or switching medications.
Nutritional targets include 60–75 g of protein per day, with higher thresholds for older adults or postbariatric patients. Calorie targets range from 1,200–1,500 kcal/d for women and 1,500–1,800 kcal/d for men. The authors also emphasize the importance of whole grains, fiber, lean protein, healthy fats, and adequate hydration.
Physical activity is recommended in three phases: gradual movement introduction, resistance training (60–90 min/wk), and sustained aerobic exercise (30–60 min/d) with two to three resistance sessions weekly. This approach targets lean body mass preservation, which has been shown to decline by 25%–40% in GLP-1 RA users.
The study’s authors advise clinicians to assess ongoing function using grip strength and six-minute walk tests, and to consider gradual tapering and continued monitoring of metabolic health, muscle strength, and dietary habits after medication discontinuation.
Source: https://medicalxpress.com/news/2025-07-side-effects-nutrition-guidance-issued.html