GLP-1 medications are everywhere in the conversation about weight—but how much do we really understand? In this episode, Dr. Lexi Giblin, Executive Director of Opal, sits down with Meredith Blumenthal, a Registered Dietitian Nutritionist in private practice, to unpack the most common misconceptions surrounding GLP-1s and body weight. Together, they explore what these medications actually do, what they don’t do, and how changes in nutrition, metabolism, and food relationship occur for those taking GLP-1s. Whether you’re a clinician, patient, or just curious, this episode offers a thoughtful, evidence-based look beyond the headlines.
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Editing by David Bazzi
Music by Aaron Davidson: https://soundcloud.com/diet75/
Sound engineering by Ayesha Ubayatilaka at Jack Straw Studios
Transcription summary provided by Rev.com
This podcast episode from “The Appetite” features Dr. Lexi Giblin interviewing dietitian Meredith Blumenthal about GLP-1 medications and their use for weight loss.
What are GLP-1s?
GLP-1s were originally developed to treat type 2 diabetes and other metabolic diseases, but were approved by the FDA for weight loss approximately four years ago [3:31]. These injectable medications work through three mechanisms: they affect the brain, digestive tract, and various organs in the body [4:06]. At higher doses, they target hunger, satiety, and appetite by essentially obliterating appetite, and they slow the rate that food leaves the stomach, causing gastroparesis [5:07].
How They Work and Concerns
The slowing of digestion actually results in less effective breakdown and absorption of nutrients [5:49]. While the medications reduce appetite, they don’t reduce the body’s nutritional needs [6:20] [6:43]. This creates a concerning situation where people may experience nutrient deficiencies similar to those seen in severe anorexia, regardless of body weight [7:57].
Screening and Risk Factors
The discussion reveals inadequate screening for eating disorders before prescribing GLP-1s [8:45]. Many patients present with binge eating concerns, but providers often miss the role of restriction in binge-restrict cycles [9:19] [10:16]. Weight stigma and lack of eating disorder training among prescribers contribute to this problem [11:07].
Long-term Use and Weight Cycling
A critical finding is that GLP-1s must be taken long-term to maintain benefits. When people stop the medication, weight regain occurs almost immediately as appetite returns [15:40] [16:15] [17:05]. The medications function similarly to dieting, and according to set point theory, may result in higher weights after discontinuation due to metabolic adaptations [24:07] [25:03] [25:31].
Muscle Loss and Harm Reduction
GLP-1s can cause significant muscle wasting because muscle tissue is easier for the body to access for energy than fat, especially when protein intake is inadequate and physical activity is limited [26:37]. For those choosing to use these medications, harm reduction strategies include regular DEXA scans to monitor muscle mass, ensuring adequate protein intake, engaging in resistance exercise, and structured eating schedules [28:07] [28:34] [29:49].
Social and Psychological Impact
The medications affect not just nutrition but social and cultural aspects of eating. Blumenthal describes reading about someone constantly explaining their limited food intake at social gatherings by saying “I’m on a GLP-1,” noting this could easily be replaced with “I have an eating disorder” [35:43] [36:22]. Food serves purposes beyond nutrition including tradition, culture, social connection, and celebration [36:39].
Safety and Accessibility Concerns
The ease of accessing GLP-1s through online clinics raises safety concerns about counterfeit medications, lack of quality control, and improper dosing [40:57] [41:30] [42:00]. The oral forms being advertised aren’t yet FDA-approved for weight loss [40:57].
Clinical Recommendations
Both speakers emphasize the importance of body autonomy while ensuring informed consent. They recommend working with both dietitians and therapists, especially for those with eating disorder histories [30:43] [32:23]. The goal is supporting individual decision-making while providing comprehensive care and relapse prevention planning [33:23] [33:47
