How Not to Diet: The Groundbreaking Science of Healthy, Permanent Weight Loss

by Michael Greger

It takes an estimated average of seventeen years before evidence from scientific research is incorporated into day-to-day clinical practice.1

If effectively the cure to the number-one killer of men and women could be ignored and get lost down some rabbit hole, what else might be buried in the medical literature?

A Harvard sociologist of science calls those arguments by anecdotes in diet books “a deliberate attempt at credibility engineering.”4 When you don’t have the science to back you up, all you have are “success” stories.

Even if you eat and absorb the same number of calories, a calorie may still not be a calorie. As you’ll learn, the same number of calories eaten at a different time of the day, in a different meal distribution, or after different amounts of sleep can translate into different amounts of body fat.

Obesity isn’t new, but the obesity epidemic is. We went from a few corpulent queens and kings, like Henry VIII and Louis VI (known as Louis le Gros, or “Louis the Fat”),18 to a pandemic of obesity, now considered to be perhaps the direst and most poorly contained public health threat of our time.

Obesity does tend to run in families, but so do lousy diets.

If you were able to steadily forage a pound of food an hour and it had 250 calories per pound, it might take you ten hours just to break even on your calories for the day. But if you were gathering something with 500 calories a pound, you could be done foraging in five hours and spend the next five focusing on your wall paintings. So the greater the energy density, the more calories per pound, the more efficient the foraging. We developed an acute ability to discriminate foods based on calorie density and instinctively desire the densest.

First, they remove the fiber, because it effectively has zero calories. Run brown rice through a mill to make it white, and you lose about two-thirds of the fiber. Turn whole-wheat flour into white flour and lose 75 percent of the fiber.

What you’re left with is CRAP, an acronym conceived by one of my favorite dietitians, Jeff Novick, for calorie-rich and processed foods.

Consider the humble potato. We’ve long been a nation of potato eaters, but they were largely baked or boiled. Anyone who has made fries from scratch knows what a pain it is, with all the peeling, cutting, and splattering. But with sophisticated machinations of mechanization, french fry production became centralized so fries could be shipped at -40°F to any fast-food deep-fat fryer or supermarket frozen food section in the country to become America’s favorite vegetable. Nearly all the increase in potato consumption in recent decades has been in the forms of french fries and potato chips.

Just to give you a sense of marketing’s insidious nature, let me share an interesting piece of research published in Nature, the world’s leading180 scientific journal. The article titled “In-Store Music Affects Product Choice” documented an experiment in which either French accordion or German Bierkeller music was played on alternate days in the wine section of a grocery store.181 On the days the French music played in the background, people were three times more likely to buy French wine, and on German music day, shoppers were about three times more likely to buy German wine. Despite the dramatic effect—not just a few percent difference but a complete threefold reversal—when approached afterward, the vast majority of shoppers denied the music had influenced their choices.

We all like to think we make important life decisions, such as what to eat, consciously and rationally. If that were the case, though, we wouldn’t be in the midst of an obesity epidemic.

Of course, it matters what you’re overeating. Some foods, like many vegetables, have such a low calorie density that you would tire from chewing before you could overdo it. You’d have to eat a wheelbarrow full of cabbage before you’d ever need to begin worrying about overindulging.

Can you think of a single major industry that would benefit from people eating less junk? “Certainly not the agriculture, food product, grocery, restaurant, diet, or drug industries,” emeritus professor Marion Nestle wrote in a Science editorial when she was chair of nutrition at New York University.

Fiber-rich food consumption can also decrease the risk of acid reflux (Gastroesophageal Reflux Disease, or GERD). The excess abdominal pressure due to obesity may push up acid

Although it may take losing as much as 20 percent of your weight to realize significant improvements in quality of life for most individuals with severe obesity,464 disease risk drops almost immediately. At 3 percent weight loss (only six pounds for someone weighing two hundred), your blood sugar control and triglycerides start to get better.465 At 5 percent weight loss, blood pressure and cholesterol improve. Furthermore, a 5 percent weight loss—just ten pounds for someone starting at two hundred—may cut the risk of developing diabetes in half.

But just because we have to breathe doesn’t mean it has to be through the end of a cigarette. Similarly, just because we have to eat doesn’t mean we have to eat junk.

This suggests subcutaneous fat, the fat under our skin, is not the problem. The metabolic insults of obesity arise from the visceral fat surrounding or even infiltrating our inner organs, like the fat marbling our muscles and livers. The way you lose that fat, the dangerous fat, is to take in fewer calories than you burn.

The most common procedure is stomach stapling, also known as a sleeve gastrectomy, in which most of the stomach is permanently removed,544 leaving only a narrow sleeve or tube of stomach so as to restrict how much food people can eat at any one time.545 It’s ironic that many patients choose bariatric surgery, convinced that “diets don’t work” for them, when, in reality, that’s all the surgery may be—an enforced diet.546

So losing weight with your fork can be more than twice as effective as the surgeons’ knives.

Then came the amphetamines. Currently, more than half a million Americans are addicted to amphetamines like crystal meth,671 but the original amphetamine epidemic was generated by doctors and drug companies.

Since you’re not treating the underlying cause—a fattening diet—the weight tends to come right back when people stop taking these drugs,

According to a national survey, a third of adults who’ve made serious efforts at weight loss have tried using dietary supplements,702 for which Americans spend literally billions of dollars every year.703 Most people surveyed mistakenly thought that over-the-counter appetite suppressants, herbal products, and weight-loss supplements had to be approved for safety by a government agency like the FDA before being sold to the public—or at least include some kind of warning on the label about potential side effects. Nearly half even thought they had to demonstrate some sort of effectiveness.704 None of that is true.

The promotion of the overconsumption of high-calorie, low-nutrient foods and beverages has been identified as the major driver of the obesity pandemic.

But why not sell apples instead of Apple Jacks or oranges instead of Orange Crush? To quote from Slick Willie Sutton’s apocryphal answer to why he robbed banks: “That’s where the money is.” The reason some of the unhealthiest foods are marketed is one of simple economics: Real food goes bad.751 Fruits and vegetables are perishable. What shareholders want is a snack cake that lasts for weeks on the shelf.

On top of that, real food doesn’t have brand names. Why would a broccoli grower put an ad on TV when you’d just as likely buy their competitor’s broccoli? The system is simply not set up to reward the sale of health-promoting food.

Tobacco is one of our great public health victories. The share of adults who smoke declined from 42 percent in 1965754 down to just 15 percent today.755 That’s about five out of twelve down to fewer than two out of twelve. Thanks to the decline, cigarettes now only kill about a half million Americans a year, whereas our diets kill many thousands more. Currently, the leading cause of death in America is the American diet.756

On products like Lay’s Chips Saveur Poulet Rôti (chicken-flavored potato chips), you’ll now see messages like Pour votre santé, pratiquez une activité physique régulière (For your health, practice regular physical activity).789 Sounds good, right? Not so fast. Anytime an industry agrees to a regulation, one should get skeptical as to its effectiveness.

The absence of the healthy message doubled the number of people choosing the healthy snack. The health message made things worse. This may be the remedy-messaging boomerang effect in action. Simultaneously offering a temptation with a reminder about how they can dig themselves out justifies the excuse to indulge. Subconsciously, it may give the chicken-y chip eater the rationalization that they can just work it off the next day at the gym, even if that day never comes.

The tobacco industry’s classic “personal responsibility” trope does have a certain philosophical appeal.796 As long as people understand the risks, shouldn’t they be free to do whatever they want with their bodies?

The tobacco industry didn’t have to convince the public that smoking was healthy to get people to keep consuming its products. It just needed to establish a controversy: Some science says it’s bad, some says it’s not so bad. Conflicting messages in nutrition cause people to become so frustrated and confused they may just throw their hands up in the air and eat whatever’s put in front of them, which is exactly what the industry wants.

The title given to the paper describing these series of experiments is “Vicarious Goal Fulfillment: When the Mere Presence of a Healthy Option Leads to an Ironically Indulgent Decision.” The thinking is that just by seeing the salad or plant-based option, people make the mental note to choose that the next time, thereby giving them the excuse to indulge now.

McDonald’s Chicken McNuggets have two and a half times more salt in the United States than in the United Kingdom,

By 2001, nearly 80 percent of all ads for weight-loss products or programs featured at least one testimonial.903 Who doesn’t love a good story?904 Scientists often assert “anecdotes aren’t data,” but human nature may favor the opposite view

On average, so little weight was lost on these types of programs that cost estimates range up to nearly $200 per pound lost.917 Most people don’t chalk up that high of a bill, though, because most don’t stick with the program for very long.

C-reactive protein levels in the blood are ideally under 1 mg/L,

Having a C-reactive protein level under 1 mg/L denotes low risk, yet the levels of most middle-aged Americans exceed this,934 suggesting most suffer from chronic inflammation.

Study subjects become 12-15 percent less physically active on high-saturated fat diets compared to low-saturated fat diets.

MRI imaging scans taken of people’s brains approximately four years apart found that those eating junky, meat-centered diets experience a significant shrinkage of their hippocampi compared to those eating more healthful diets.

Researchers put people on a high-fat, ketogenic diet and confirmed a blunting of cognition, including impaired reaction times and attention, within seven days.1014

Even one bad meal a day for four days can impair our brain function. Australian researchers randomized men and women to eat either a breakfast high in saturated fat and added sugars or a healthier breakfast for four consecutive days. That’s all it took to cause a significant loss in hippocampus-dependent learning and memory.

In the Dietary Inflammatory Index, the single most anti-inflammatory food is the spice turmeric, followed by ginger and garlic, and the most anti-inflammatory beverage is green or black tea. The two most anti-inflammatory food components are fiber and flavones.1021 Dietary fiber is found in all whole plant foods, but it is most concentrated in legumes, such as beans, split peas, chickpeas, and lentils.

the benefits of the omega-3s are offset by the industrial toxins that now contaminate much of the aquatic food chain.1033

An analysis of chicken feathers found that the poultry industry appears to feed the birds everything from arsenic1040 to Prozac.1041 (Poultry producers say feeding caffeine “keeps the chickens awake so that they eat more and grow faster.”

By the time we hit early adulthood, the total number of fat cells in our bodies remains fairly stable.1054 When we gain or lose weight, we are pretty much just enlarging or shrinking our existing fat cells. Starting out with a higher number of fat cells or gaining more later in life may make it easier to put on pounds, harder to lose them, and more difficult to maintain weight loss.1055

What’s more, each fat cell we make may be at the expense of one fewer bone, cartilage, or muscle cell.

How are we exposed to PPAR-γ-activating organotin compounds? Mainly through food, especially from fish and other seafood.

but for other plastic containers, keep an eye out for recycle codes 3 and 7, as those indicate items that are more likely to contain high levels of BPA.

In 2015, when meat was officially classified as a “known carcinogen” or a “probable carcinogen” depending on whether or not it was processed,

toxicologists suggest limiting children’s consumption of beef, pork, and chicken to no more than five servings a month, an average of no more than one serving every six days or so.1130 In Europe, lamb is the most contaminated and the recommendation calls for adults to eat no more than a single serving every four or five months.