Demystifying Nutritional Consequences of Pharmacological Weight Loss and Performance Enhancement-A Critical Narrative Review

This critical narrative review examines the nonmedical or aesthetic repurposing of pharmacological agents to accelerate weight loss, suppress appetite, manipulate fluid balance, and alter body composition in glamour-, fitness-, and appearance-oriented settings. The review uses the term “chemical diet” as an interpretive framework for this pattern of use and proposes “pharmacological malnutrition” as a conceptual description of drug-associated nutritional vulnerability, rather than as an established clinical diagnosis.

Incretin-based therapies have substantial clinical value when prescribed for medically indicated obesity or metabolic disease under appropriate supervision. However, their aesthetic repurposing outside clinical governance may create nutritional and safety concerns, particularly when appetite suppression, gastrointestinal intolerance, restrictive eating, discontinuation-related weight regain, or compounded and counterfeit products are involved. Metformin is discussed mainly because of mechanistic plausibility, vitamin B12 relevance, and potential interaction with training adaptation, rather than because of strong evidence for widespread aesthetic misuse. Stimulants, β2-agonists, diuretics, thyroid hormones, anabolic-androgenic steroids, and selective androgen receptor modulators represent distinct risk categories, with hazards differing by evidence strength, severity, reversibility, and likelihood of interaction.

The chemical diet is best understood as an interface between pharmacology, nutrition, and public health rather than simply as off-label drug use. Its highest risk forms involve nonmedical use, pharmacological stacking, restrictive intake, dehydration practices, and uncertain supply chains. Potential consequences include gastrointestinal intolerance, impaired dietary adequacy, lean mass loss, electrolyte instability, renal stress, arrhythmogenic risk, and exposure to falsified, counterfeit, or compounded products. Greater regulatory oversight, nutrition-focused monitoring, and careful distinction between supervised therapy and unsafe aesthetic repurposing are needed.