How Not to Diet
by Michael Greger · 2019
Michael Greger follows How Not to Die with a weight-loss-specific book, reviewing the research on which foods and habits are actually associated with sustainable weight loss versus which are diet-industry noise.
Worth reading? How Not to Diet is thorough to a fault -- Greger reviews an enormous body of nutrition research, and the book's insistence on citing its sources is genuinely rare in the diet-book category. Its clear point of view is a whole-food, plant-based eating pattern, and readers should know that's the lens the research gets filtered through going in. The length and density make it a reference book more than a casual read.
| Full Title | How Not to Diet: The Groundbreaking Science of Healthy, Permanent Weight Loss |
|---|---|
| Author | Michael Greger |
| Published | 2019 |
| Publisher | Flatiron Books |
| Category | Health & Fitness |
The Verdict
Greger’s insistence on citing his sources is the book’s biggest strength and its biggest obstacle. You get an unusually rigorous diet book, and also a genuinely long one – this isn’t a weekend read.
The calorie-density argument is the most useful practical takeaway: eating foods that are naturally lower in calories per volume makes portion control less of a constant fight. Just go in aware that Greger has a clear point of view (whole-food, plant-based eating), and the research gets organized to support it.
Read it if you want a research-heavy case for sustainable weight loss and don’t mind a long, citation-dense read. Skip it if you want a simple plan without engaging with the underlying studies – this book asks more of you than that.
you want a heavily citation-based review of weight-loss research, organized around a whole-food, plant-forward eating pattern, from a doctor who footnotes essentially every claim
you want a simple, low-effort diet plan -- this book is long, dense with citations, and asks you to engage with the underlying research rather than just follow a meal plan
Book Summary
Greger structures the book around a "Weight Loss Booster" framework, reviewing research on specific foods, meal timing, and habits he argues are associated with easier, more sustainable weight loss -- higher-fiber, lower-calorie-density whole foods chief among them.
A recurring theme is calorie density rather than calorie counting: Greger argues that whole plant foods like vegetables and legumes are naturally lower in calories per volume than processed and animal-based foods, making it easier to eat satisfying portions without needing to consciously restrict.
The book reviews research on specific weight-loss aids -- including timing of meals, sleep, stress, and specific foods like vinegar or particular spices -- with heavy citation of primary studies, while being clear that no single food is a magic solution on its own.
Greger is explicit that his recommendations point toward a whole-food, plant-based diet as the pattern best supported by the research he reviewed, which readers should weigh as his stated point of view rather than a neutral survey of all dietary approaches.
Top 7 Lessons from How Not to Diet
- Calorie density -- calories per volume of food, not just per serving -- may make whole plant foods easier to eat filling portions of without needing to consciously count calories.
- Fiber-rich whole foods are associated in the research Greger reviews with greater satiety per calorie compared to more processed, lower-fiber foods.
- Highly processed foods tend to be calorie-dense and low in fiber and water content, a combination the book associates with easier overeating.
- Sleep and stress management are treated as real factors in weight management, not separate from diet, since both affect hunger hormones and eating behavior.
- No single 'superfood' or supplement is presented as a standalone weight-loss solution -- Greger frames food choices as cumulative patterns, not individual fixes.
- The book reviews research on specific practices like pre-meal vinegar or particular spices as modest aids, not primary drivers, of weight change.
- Greger's own dietary point of view (whole-food, plant-based eating) is the lens the research gets filtered and organized through, which readers should factor in when weighing the book's conclusions.
Frequently Asked Questions
Is How Not to Diet worth reading?
If you want a heavily researched, citation-based case for a whole-food, plant-based approach to weight loss, yes -- just expect a long, dense read rather than a quick diet plan.
What is How Not to Diet about?
Michael Greger reviews weight-loss research, arguing calorie density and fiber-rich whole foods matter more than calorie counting, and building the case for a plant-forward eating pattern.
Does How Not to Diet recommend a specific diet plan?
It points toward a whole-food, plant-based eating pattern as the approach best supported by the research Greger reviewed, rather than prescribing a rigid meal plan.
Is How Not to Diet backed by scientific citations?
Yes -- it's unusually heavily footnoted for a diet book, citing primary research throughout.
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