Review sets nutrition targets for patients on GLP-1 obesity drugs

A narrative review published in Obesity Pillars, the journal of the Obesity Medicine Association, lays out specific daily nutrition targets for people taking GLP-1 medications and states that many patients on these drugs receive no nutrition advice at all ^[1]. The article, "Application of nutrition interventions with GLP-1 based therapies: A narrative review of the challenges and solutions," appears in the journal's Volume 16 as article 100205, dated December 2025, and is open access ^[1].

The authors are Angela Fitch, Linda Gigliotti and Harold Edward Bays ^[1]. Their review examines the challenges of eating well during GLP-1 treatment and offers practical targets for the clinicians who prescribe these drugs.

The numbers in the review

Protein: 1 to 1.5 grams per kilogram of body weight per day, paired with resistance training, to help preserve muscle mass ^[1]. Fluids: more than 2 to 3 liters a day, with the review noting that GLP-1 therapy may reduce thirst perception, so feeling thirsty may not track with what the body needs ^[1]. Fiber: 21 to 25 grams a day for women and 30 to 38 grams for men ^[1]. The review also calls for regular eating schedules with planned portion sizes, and it advises limits on high-fat and spicy foods ^[1].

The review ties those targets to two problems it describes as common in this group: loss of muscle mass, including the risk of sarcopenic obesity, in which low muscle mass accompanies excess body fat, and poor nutrition ^[1]. It describes obesity as a heterogeneous, systemic chronic disease with a complex mix of causes ^[1].

Who delivers the advice

The review's concern is not only what patients eat but whether anyone discusses it with them. It says many people on GLP-1 based therapies do not get appropriate nutrition advice and struggle to maintain their weight reduction ^[1]. It says physicians should work with dietitians and other healthcare providers to deliver counseling that is patient-centered and matches the individual's needs and preferences ^[1].

That counseling, as the review describes it, covers macronutrient, micronutrient and fluid intake, mental health, sleep hygiene, physical activity, and medication adherence and persistence ^[1]. The authors also call for evidence-based nutrition guidelines to give healthcare professionals a consistent framework based on rigorous scientific research ^[1].

Why it matters for patients

GLP-1 based therapies are prescribed for type 2 diabetes and, increasingly, for people with overweight or obesity as an addition to a reduced-calorie diet and more physical activity ^[1]. When appetite drops, food and fluid intake usually drop with it. That is where the review's targets become relevant: protein and resistance training for muscle, fiber for digestive health, and fluids for hydration in people who may no longer feel thirsty ^[1].

Because the review says this counseling is often missing, patients may not hear these targets unless a clinician or dietitian raises them. The review does not state how many patients currently go without nutrition care, so the size of that gap has not been disclosed ^[1].

What is not yet known

This is a narrative review of existing literature, not a new clinical trial, so it does not report new patient outcomes from testing the targets it proposes ^[1]. It also does not address how the targets should be adjusted for people with kidney disease, older adults, or other specific groups; those adjustments have not been reported ^[1]. The review's authors note that patients on GLP-1 based therapies should be closely monitored and given comprehensive nutrition and lifestyle support, but they do not specify how often that monitoring should happen ^[1].