The claims in this book rest on the sources below. I have kept citations out of the chapters so the reading stays clean, but nothing in these pages rests on my say-so alone.

A note on how to read them: a systematic review pools many trials and is usually the strongest evidence here — as strong as the trials it pools; a single randomized trial is strong for what it measured; a guideline or consensus statement is expert judgment — valuable, and honest ones say where their evidence is indirect. Where a study was small or industry-sponsored, that is worth knowing, and I have said so.

The evidence gap (Chapter 1)

Santos de Paulo et al., 2026 — Dietary strategies with GLP-1 and GIP/GLP-1 therapy: systematic review of 16 randomized trials — 7,096 participants; no best diet identified.
Jansson et al., 2026 — Evidence gaps in dietary reporting across 41 randomized trials — only two trials meaningfully assessed what participants ate.
Spreckley et al., 2026 — Nutrition strategies for incretin therapies: scoping review — twelve studies; optimal strategy remains uncertain.

Appetite, intake, and the stomach (Chapter 2)

Blundell et al., 2017 — Semaglutide and appetite, energy intake, and food preference — small crossover trial; daily intake fell roughly a quarter.
Tronieri et al., 2026 — Semaglutide, energy intake, and appetite over 60 weeks — reduced intake persisted as subjective appetite effects faded.
Martin et al., 2025 — Tirzepatide and ingestive behavior: 6-week randomized trial — smaller meals and fewer cravings; no change in deliberate restraint; industry-sponsored.
Jalleh et al., 2024 — GLP-1 receptor agonists, tirzepatide, and gastric emptying — effects vary and can lessen over time.
Wilding et al., 2021 — STEP 1: weekly semaglutide in adults with overweight or obesity — landmark randomized trial context for treatment effects.
Jastreboff et al., 2022 — SURMOUNT-1: weekly tirzepatide for obesity — landmark randomized trial context for treatment effects.

Muscle, protein, and movement (Chapter 4)

Look et al., 2025 — Body composition in SURMOUNT-1 — small DXA substudy; about a quarter of weight lost was lean mass in both groups; industry-sponsored.
Prado et al., 2024 — Muscle matters: medically induced weight loss and skeletal muscle — commentary; lean loss roughly a quarter to over a third across trials.
Kokura et al., 2024 — Higher protein intake during weight loss: meta-analysis — preserved muscle mass; general weight-loss populations, not GLP-1-specific.
Lundgren et al., 2021 — Weight-loss maintenance with exercise, liraglutide, or both — the combination improved body composition and fitness most.

Clinical guidance this book leans on (Chapters 3, 5, 6, 7)

Mozaffarian et al., 2025 — Nutritional priorities to support GLP-1 therapy: joint advisory — four professional societies; nutrient density, protein, resistance activity, dietitian support.
Sievenpiper et al., 2025 — Nutritional and lifestyle supportive care with GLP-1 therapy: Delphi consensus — 52 statements; the authors state the evidence is primarily indirect.
Wharton et al., 2020 — Obesity in adults: Canadian clinical practice guideline — individualized medical nutrition therapy rather than one prescribed diet.
Almandoz et al., 2024 — Nutritional considerations with antiobesity medications — practical review of protein, fiber, fluids, and monitoring; industry-supported.

The relationship with food (Chapter 7)

Bartel et al., 2024 — GLP-1 medications in eating disorder populations — evidence too limited for firm conclusions; supports screening and referral.

This page lists sources, not medical advice. Nothing here replaces a conversation with your own physician.