Why Diets Make Us Fat by Sandra Aamodt Summary

Why Diets Make Us Fat by neuroscientist Sandra Aamodt challenges conventional weight-loss wisdom, arguing that chronic dieting disrupts the body’s natural weight-regulation system. The book explores how repeated dieting leads to metabolic slowdown, increased hunger, and long-term weight gain by fighting against the brain’s “set point.” Aamodt critiques low-fat diet trends and emphasizes intuitive eating as a sustainable alternative to restrictive calorie counting.

This book is ideal for anyone frustrated with yo-yo dieting, health professionals seeking neuroscience-based insights, or individuals interested in the science of metabolism. It’s especially valuable for parents, policymakers, and those skeptical of mainstream diet culture. Aamodt’s accessible writing bridges academic research and practical advice.

Yes—Aamodt’s evidence-based approach debunks pervasive myths about weight loss, offering a fresh perspective on obesity research. The book synthesizes decades of neuroscience and nutrition studies, making it a standout resource for understanding why diets fail 95% of people long-term. Critical praise highlights its relevance for rethinking societal approaches to health.

Sandra Aamodt holds a PhD in neuroscience, served as editor-in-chief of Nature Neuroscience, and has analyzed over 5,000 neuroscience studies. Her prior books, Welcome to Your Brain and Welcome to Your Child’s Brain, established her as a leading science communicator. This expertise underpins her critique of diet-industry pseudoscience.

The set point theory posits that the brain regulates weight within a genetically influenced range through hormonal and metabolic adjustments. Aamodt explains that dieting triggers starvation responses—slowed metabolism, heightened calorie storage—which push weight back toward the set point. This biological “defense system” makes sustained weight loss nearly impossible for most people.

Aamodt links low-fat diet trends to increased refined carbohydrate consumption, which spikes insulin levels and promotes fat storage. By prioritizing fat reduction over nutrient quality, food manufacturers created products that disrupt satiety signals, leading to overeating. The book cites historical data showing obesity rates tripling post-1970s fat-phobic policies.

Aamodt advocates for intuitive eating: tuning into hunger cues, reducing stress around food, and avoiding moral labels like “good” or “bad” foods. She emphasizes consistent sleep, mindful movement, and eliminating restrictive rules to stabilize metabolism. This approach aligns with the body’s natural weight-regulation mechanisms.

Repeated dieting trains the body to conserve energy, reducing basal metabolic rate by up to 15%. Aamodt explains that this adaptation persists post-diet, making regain likely. Over time, muscle loss and hormonal shifts (e.g., leptin reduction) further entrench a higher set point, creating a cycle of weight fluctuation.

Aamodt highlights insulin’s dual role: regulating blood sugar and directing fat cells to store energy. High-carb, low-fat diets cause insulin spikes that block fat release, increase hunger, and promote calorie hoarding. This process, exacerbated by processed foods, traps individuals in a “starve-binge” metabolic pattern.

Unlike prescriptive diet guides, Aamodt’s work focuses on systemic biological and cultural factors driving obesity. It aligns with anti-diet movement principles but adds neuroscientific rigor, distinguishing it from anecdotal approaches. The book complements works like The Obesity Code while critiquing calorie-centric models.

Yes—Aamodt positions intuitive eating as the sustainable alternative to dieting. By rebuilding trust in hunger/fullness cues and reducing food anxiety, individuals can stabilize near their natural set point. Studies cited show intuitive eaters have lower diabetes risks and better psychological health than chronic dieters.

Aamodt argues that diets ignore biological adaptability, treating obesity as a “willpower failure” rather than a mismatch between modern food environments and evolutionary biology. She dismantles calorie-counting myths, showing how restrictive eating triggers rebound overeating and worsens metabolic health long-term.