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What to Eat When: A Strategic Plan to Improve Your Health and Life Through Food

Shows why the timing of meals matters as much as their content, and how to shift most of your calories into the morning while choosing whole foods, good fats and plant and sea proteins.

Table of Content

Most people who try to eat better change what is on the plate and ignore the clock. In What to Eat When, physicians Michael Roizen and Michael Crupain, writing with journalist Ted Spiker, argue that timing deserves equal attention. Because insulin resistance climbs over the course of the day, the same carb-heavy meal pushes blood sugar higher in the evening than in the morning.

Their plan follows from that: eat whole foods, good fats and plant and sea proteins, and eat most of them early, in daylight, at steady times and with attention. The book moves from how food works inside you to a month-long plan for shifting your meals, with fallbacks for days when you are tired, angry or rushing. The goal is concrete: about three quarters of your calories eaten by the end of lunch.

Two foods can deliver the same calories and still leave you in very different shape an hour later. The difference lies in how fast fuel reaches your blood, and in which fats you let onto the plate.

Eating too much explains only part of why weight piles on. A hormone that switches off fat burning, and the hour at which you eat, shape the outcome as much as the amount on the plate.

Night workers gain more weight than day workers, and mice eating identical calories end up lean or heavy depending on when they eat. The pattern points to one simple change in your daily schedule.

Making breakfast the largest meal sounds impossible when breakfast means toast. One of the authors solves it with a habit from his own kitchen, and a study suggests why a boring menu can help.

Most people eat the bulk of their calories after lunch without realizing it. A month of small, measured steps can move that weight toward the morning and clean up what is on the plate at the same time.

Your body knows you have had enough well before you feel it. A single raisin, eaten very slowly, shows what you have been missing at every meal and why fast eaters so often overeat.

Exhaustion, anger and a packed schedule are when good eating plans usually fall apart. The authors keep a ready answer for each, from a spiced snack baked in advance to a trick for oversized restaurant portions.

Four in ten cancers may be preventable, and one style of eating cut heart attack risk sharply in a major study. Small changes in the grocery basket turn out to carry stakes measured in years.

What to Eat When treats the day as a slope. Food eaten in the morning meets a body that handles sugar well. The same food at midnight meets a body already resisting insulin and inclined to store fat. The authors’ target follows from that: whole foods, good fats, plant and sea proteins, and about 75 percent of your calories eaten at breakfast and lunch.

Spend a few days writing down when you eat, then set aside a quarter of tonight’s dinner and have it for breakfast. Pick two meals you like and repeat them until the rhythm feels normal. To handle an evening sweet craving, the authors propose a disguised dessert of Greek yogurt stirred together with almond butter, a little cocoa powder, and one spoonful of dark chocolate.

The largest change may be the simplest. Breakfast stops being the meal you skip on the way out the door and becomes the one that carries your day, while the kitchen closes before the sun goes down.

About this book

What is this book about?

Most diet advice is about what to eat. Physicians Michael Roizen and Michael Crupain, writing with journalist Ted Spiker, argue that when you eat deserves equal attention. Insulin resistance rises steadily through the day, so an identical meal does more damage at night than it would at breakfast. Studies of night workers, mice and overweight dieters, they show, all point the same way. The book starts with the basics of carbohydrates, proteins and fats. It explains how blood sugar spikes and insulin resistance lead to stored fat, then turns to the body's circadian rhythm. From there it builds a practical plan: eat dinner for breakfast, keep meals inside daylight hours, repeat a few favorite recipes, and spend one month moving calories earlier and swapping poor choices for better ones. Readers also get fallbacks for hard moments, from roasted chickpeas when hungry and angry to convenience store choices on busy days and portion tricks on vacation. The authors also cover the eating patterns they link to lower cancer and heart disease risk. The target is simple: about 75 percent of daily calories eaten at breakfast and lunch.

Book Information

Rating:

Genre:

Health & Nutrition

Topics:

Longevity, Metabolism, Nutrition

Publisher:

Disney Publishing Worldwide

Language:

English

Narrator:

Meredith

First published:

December 31, 2019

Pages:

352

Length:

15 min 15 sec

Get the book:

Amazon

Who it's for

  • Breakfast-skipping professionals

    Busy professionals who skip breakfast and eat most of their food at night.

  • Calorie-counting dieters

    People trying to lose weight who have counted calories but never looked at meal timing.

  • Shift workers, travelers, stress-snackers

    Night and shift workers, frequent travelers and stress snackers who want practical fallbacks.

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About the Author

Michael Roizen

Michael Roizen holds board certification in both anesthesiology and internal medicine. The Cleveland Clinic made him the first chair of its Wellness Institute, and he has also been its chief wellness officer. He co-invented the drug methylnaltrexone. Michael Crupain, a preventive medicine physician, teaches at the Johns Hopkins Bloomberg School of Public Health. He earned two Emmy Awards as medical director of The Dr. Oz Show and led Consumer Reports' Food Safety and Sustainability Center. Ted Spiker, a magazine writer, served the University of Florida as interim chair of journalism and coauthored YOU: The Owner's Manual.

Ratings & Reviews

Ratings at a glance

4.4

Overall score based on 439 ratings.

What people think

Listeners find the book educational and accessible, valuing the way it blends classic and contemporary research while highlighting the importance of both food choice and timing. Furthermore, the work earns praise for its wellness advantages, especially its concentration on circadian rhythms and nutrient timing, alongside its success in aiding weight reduction. Listeners also appreciate the incremental method for shifting habits and consider the advice practical. Nonetheless, the culinary component gets varied feedback, as several listeners mention a lack of specific meal plans and recipe instructions.

Top reviews

Isaiah

What to Eat When completely shifted my perspective on my daily routine by focusing on biological timing rather than just calorie counting. The doctors explain the science behind our internal clocks in a way that feels both urgent and manageable. Personally, I found the advice on eating only when the sun is up to be the most effective weight loss tool I've ever tried. The book is a treasure trove of small tips—like how walnuts help with sleep or why cherries are good for pain management. I loved that it wasn't just about 'don't eat this,' but rather 'eat this at this specific time for this specific result.' The layout is beautiful, and the writing style is engaging enough to keep you turning pages even through the denser scientific sections. It’s a functional guide that I keep on my kitchen counter for quick reference when I’m feeling under the weather. Truly a must-read for anyone serious about longevity.

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Sing

Finally got around to reading this strategic guide, and the emphasis on 'when' you eat is a game changer for my digestion. I’ve always been a late-night snacker, but the logic regarding our circadian rhythms convinced me to shift my calories to earlier in the day. The book is incredibly easy to read and doesn't drown you in overly complex medical jargon, which I appreciated. Not gonna lie, trying to get 75% of my food in before 2 PM is a massive adjustment, but I already feel less bloated. The inclusion of National Geographic photos makes the book visually stunning, even if the recipe section felt a bit thin on actual instructions. It’s not a traditional diet book, which is why I think it actually works for long-term health. I’m giving it four stars because some of the advice on caffeine and fats feels a little bit contradictory at times.

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Gor

The chapter on brain health alone made this worth the purchase for me, especially as I get older and worry about cognitive decline. Roizen and Crupain do a great job of breaking down how certain foods like blueberries and leafy greens interact with our biology at different times. I appreciate that they don't just focus on weight loss, though that is a nice side effect of following their sunrise-to-sunset eating schedule. Gotta say, the 'What to Eat When You’re Hangry' section was a lifesaver for my daughter, who finally understands why she crashes in the afternoon. My only real gripe is that the book can be a bit repetitive, hammering the same points about breakfast over and over. Still, the information is presented clearly, and the gradual approach to habit change feels more realistic than a crash diet. It’s a solid resource for anyone looking to optimize their energy levels throughout the day.

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Watchara

Picked this up during a health kick, and I appreciate that the authors don't demand overnight perfection despite their strict stance on certain foods. The book focuses on strategy over willpower, which is a refreshing change from the usual 'just try harder' mantra of most diet books. I’ve started making my lunches my biggest meal of the day, and the difference in my afternoon energy levels is night and day. Truth is, I probably won't give up my occasional soda, but I am drinking way more water and planning my meals a week in advance now. The writing is snappy and the chapters are short enough to read during a coffee break. I would have liked more specific meal details, as the 'recipes' are more like suggestions than actual instructions. Overall, it’s a very helpful guide for anyone looking to align their eating habits with their natural biology.

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Yaowares

To be fair, I was skeptical about the whole 'circadian rhythm' approach to dieting, but the doctors make a very compelling case. This isn't just about what you put in your mouth; it's about honoring the biological clock that governs every cell in your body. I found the sections on what to eat when you're under the weather or feeling stressed particularly insightful and practical. Not gonna lie, the authors' backgrounds with the Dr. Oz show made me hesitate, but the actual content of the book is grounded in real research. It’s a very easy-to-digest read that organizes a lot of complex information into actionable steps. My only complaint is the stance on eggs—I’m not ready to give up my yolks just yet! But the general principle of eating earlier and lighter in the evening has already helped me sleep better. It’s a functional, well-designed book.

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Bo

Is it really revolutionary to eat a salmon burger at 8 AM? The authors seem to think so, but for many of us already in the health world, this is pretty basic stuff. I found the book informative enough for a beginner, but seasoned health nuts won't find much that hasn't been covered in 'Prevention' or 'Men’s Health' over the last decade. Frankly, the no-cheat-day policy is a bit much; imagine never having a piece of chocolate cake again just to hit age 100! I liked the specific chapters on what to eat for certain ailments, like brain function or prostate health, as it allows for a pick-and-choose reading style. However, the lack of detailed meal plans and recipes makes it hard to actually put the theory into practice. It’s a decent primer on nutrient timing, but it could have been much shorter and less padded. A solid three-star read for the curious.

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Mikael

As someone who has struggled with weight for years, I found the strategy here interesting but somewhat familiar. The core message is 'eat breakfast like a king, lunch like a prince, and dinner like a pauper,' which isn't exactly a new concept in the nutrition world. In my experience, the authors spend a lot of time patting themselves on the back for 'discovering' things that have been around for ages. That being said, the scientific explanation of why our bodies process insulin differently at night was very eye-opening. I tried some of the snack suggestions and found them tasty, though I wish there were more of them. The book is easy to breeze through, but it feels like it’s missing a concrete plan to help you transition into this lifestyle. It’s good for a quick shot of motivation, but don't expect a radical departure from standard health advice. It's more of a refinement than a revolution.

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Logan

Ever wonder why you feel sluggish after a big dinner? This book explains the biology behind that 'food coma' and offers a strategic plan to avoid it by front-loading your calories. While I enjoyed the scientific insights, the book felt like it was written for people who have never read a health magazine in their life. 'Don't eat sugar' and 'drink more water' are tips we've heard a thousand times, and they occupy quite a bit of space here. Honestly, the most valuable part was the breakdown of specific foods for specific needs, like garlic for cancer prevention. I was disappointed that for a book co-authored by a producer and an editor, there were so many sections that felt like 'fluff.' The absence of a robust recipe section is also a major drawback if you're looking for a complete lifestyle overhaul. It’s a decent book to borrow from the library.

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Thanit

After hearing about Dr. Roizen’s work, I expected more substance and less self-congratulatory filler. The first few chapters are bogged down by the authors trying to establish their celebrity credentials, which feels unnecessary for a book about science. Truth is, the Dr. Oz connection was a major turn-off for me, as I prefer my medical advice without the sensationalism. They suggest avoiding egg yolks and using seed oils, which contradicts a lot of current nutritional research I've seen elsewhere. While the idea of eating with the sun is interesting, the 'revolutionary' advice like eating a salmon burger for breakfast isn't exactly groundbreaking. It felt like a 50-page concept stretched into a 300-page book to satisfy a publisher's requirements. I didn't find the 'strategy' particularly easy to implement given the rigid rules. If you're looking for a deep dive into nutrition, this might leave you wanting more authentic help and less hype.

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Narongrit

Look, I wanted to love this, but the level of restriction is just unsustainable for a normal human being with a social life. The authors demand total perfection with zero room for error, which feels like a recipe for disordered eating rather than health. They tell you to avoid sugar and fried foods entirely—no exceptions—which we all know, but who actually lives like that forever? I was also disappointed by the lack of actual recipes; for a book about food, there is surprisingly little guidance on how to cook these meals. The tone felt a bit condescending, as if they assume the reader has no basic knowledge of nutrition. I’m allergic to most fish, so their heavy emphasis on salmon and seafood made half the book useless for my specific needs. To be fair, the concept of the circadian rhythm is interesting, but the execution here is too rigid. I can't see myself sticking to this for more than a week.

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Questions about this book

The authors argue that when you eat matters as much as what you eat. Insulin resistance in the body climbs as the hours pass, so the same carb-heavy meal pushes blood sugar up further in the evening. Their answer is a diet built on unprocessed foods, healthy fats and proteins from plants and the sea, with about 75 percent of daily calories eaten at breakfast and lunch, within daylight hours.

It means dropping the idea that some foods belong to certain times of day. One of the authors makes four small salmon burgers with broccoli and quinoa at dinner, eats one and saves three for the next morning. A gentler start is Greek yogurt with berries at breakfast, a lunch of plants and whole grains, and a simple dinner such as grilled chicken with salad.

Spend the first few days recording what you eat and when, and estimate each meal’s share of your calories. Then save one quarter of a large dinner for the next day, later a second quarter, and start eating dinner earlier. In the second half of the month, look at processed food, simple carb snacks and vegetable servings, and make swaps such as a whole grain bagel with avocado and tomato.

For tiredness, they advise skipping candy and soda, whose quick lift ends in a crash, and choosing a snack with healthy fat, protein and fiber, such as avocado toast. For hanger, they recommend roasted chickpeas tossed with olive oil and spices like cayenne, garlic and rosemary, baked at 425 degrees Fahrenheit for 30 minutes. They note that legumes control blood sugar and hunger better than animal protein.

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