How Not to Diet

by Michael Greger

This loss of water weight helps explain why low-carb diets have been such “cash cows”4164 for publishers over the last 156 years.4165 As one weight-loss expert noted, “Rapid water loss is the $33-billion diet gimmick.”4166

Less fat in the mouth means less fat on the hips, even when taking in the same number of calories.4168

For millennia, our ancestors often may have consumed only one large meal a day or went several days at a time without food.4229

Instead of 5:2, what about 25:5, spending five days a month on a “fasting-mimicking diet”? Longevity researcher Valter Longo designed a five-day meal plan to try to simulate the metabolic effects of fasting by being low in proteins, sugars, and calories with zero animal protein or animal fat. By making it plant-based, he was hoping to lower the level of the cancer-promoting growth hormone IGF-1 related to animal protein consumption, which he accomplished, along with a drop in markers of inflammation, after three cycles of his five-days-a-month program.4310

One hundred men and women were randomized to consume his fasting-mimicking diet (FMD) for five consecutive days per month or maintain their regular diets for the duration of the study. After three months, the FMD group was down about six pounds compared to control, with significant drops in body fat and waist circumference accompanied by a drop in blood pressures.

Three months after completion of the study, some of the benefit appeared to persist, suggesting the effects may last for several months. However, it’s unclear if those randomized to the FMD group used it as an opportunity to make positive li...

The whole diet appears to be mostly a few dehydrated soup mixes of vegetable, mushroom, and tomato, herbal teas like hibiscus and chamomile, kale chips, nut-based energy bars, an algae-based DHA supplement, and a multivitamin dusted with vegetable powder.

But why spend fifty dollars a day on a few processed snacks when you could instead eat a few hundred calories a day of real vegetables?

“Eating breakfast and lunch 5–6 h[ours] apart and making the overnight fast last 18–19 h[ours] may be a useful practical [weight control] strategy.”4345

Not only does alcohol carry its own calories, it may end up increasing intake. I mean, the whole purported point of an aperitif is to stimulate appetite. When people drink a glass of wine or beer before lunch, they may eat more food than if they had drunk the same volume and calories of grape juice and other nonalcoholic beverages.

Those drinking a beer with quadruple the regular alcohol content ate two hundred calories more at a subsequent meal compared to those drinking a regular beer—and that was above and beyond the beer’s own calories.4532 So it’s like a reverse-preload effect that just makes things worse.

Four Rules of Sleep Conditioning:4658 Go to bed only when you’re sleepy. Only use the bed for sleep (and sex). No reading, eating, or screen time. If you can’t fall asleep within fifteen to twenty minutes or so, get up, leave the bedroom, and don’t go back until you’re sleepy again. Repeat as necessary. Get up at the same time every morning no matter how little sleep you have had.

Four Rules of Sleep Hygiene:4660 Exercise regularly. Avoid caffeine, nicotine, and alcohol before bedtime. Make the bedroom dark, cool, comfortable, and quiet. Establish a relaxing bedtime routine.

The best time to exercise to improve sleep appears to be four to eight hours before bedtime,4661 though it appears to be a myth that exercising right before bed is somehow disruptive to sleep.4662

Relaxation techniques, such as massage,4670 mindfulness meditation,4671 and soothing music,4672 may also help. So, too, may taking a relaxing hot bath or shower. One of the reasons late-night eating can delay sleep is that it may interfere with the drop in core body temperature that normally occurs around bedtime,4673 which is thought to be one of the cues that it’s time for bed.

So wouldn’t that make a hot shower counterproductive? No. As soon as you step out of the bath, your rapid decline in skin temperature can accentuate the natural nighttime drop and improve sleep.4674 Even just a warm footbath may help you fall asleep about fifteen minutes faster.4675

What about Bikram—or hot—yoga, practiced at a humid 100°F and purported to burn a thousand calories a session? That’s a bit of a stretch. (Ahem.) When put to the test, calorie expenditure during hot yoga was no more fat-burning than room-temperature yoga.4745 Overall, yoga doesn’t appear to have any special weight-reducing benefits,4746 but the best form of exercise is the one you’ll actually do, so if you enjoy it, go for it. Namaste.

Mindfulness-based modalities can help with stress management4805 and self-control,4806 and can decrease impulsive,4807 binge, and emotional eating, all of which might facilitate weight management.

Five hundred men and women suffering from anxiety and depression were placed on a whole food, plant-based diet and lifestyle program. Most dropped out within the first two weeks because they felt the program was “too rigorous” for them. However, the majority of those who stuck with the program experienced substantial improvements in mood and a “large improvement or full remission” of anxiety symptoms. Most who had been suffering from fatigue and pain got better and, over the twelve-week study period, lost an average of six pounds. What was most remarkable is that three months after the study ended, they were down a total of fifteen pounds, suggesting they stuck with it on their own. Exercise and twenty minutes of relaxation a day were also prescribed with the whole food, plant-based diet, though, so it’s impossible to isolate out the effects of what they ate.4822

There are randomized controlled trials of plant-based diets that have resulted in significant improvements in anxiety, fatigue, depression, and emotional well-being utilizing dietary changes alone,4823 but is that directly because of the diet or indirectly due to the augmented weight loss?

if you randomize people to remove all meat and eggs from their diets, you can get a significant drop in stress levels within just two weeks, compared to those who kept eating fish or a third group who continued to include all animal foods. So even before significant weight loss could occur, the researchers suggest “individuals who eliminate meat, fish, and poultry may cope better with mental stress.”4826

A single meal high in animal protein can nearly double the level of the stress hormone cortisol in the blood within a half hour of consumption, more than twice that of a meal closer to the recommended level of protein.4827 Give someone a meal of crabmeat, tuna, and cottage cheese, and the level of cortisol in their saliva shoots up within the hour. Instead, give someone some barley soup and a vegetable stir-fry, and cortisol levels drop down after the meal.

The concern is you might “chronically stimulate” your adrenal glands.4829 We don’t always have control over the stress in our lives, but at least we can make some dietary tweaks to help keep cortisol under control.

animal protein intake during pregnancy has been associated with children becoming overweight later in life.4848

Whereas babies of meat-free mothers have lower cortisol levels,4849 higher-meat diets are considered to present a “metabolic stress” to the mother, effectively reprograming the adrenal glands of their children, leading to lifelong elevations of stress hormones in their blood.

Every daily portion of meat consumed during late pregnancy was linked to about a 1 percent greater fat mass in their children by the time they reached adolescence.

The adult children of mothers who ate more meat during pregnancy don’t just walk around with higher baseline stress hormone levels but also appear to react more negatively to whatever life throws at them. Researchers tracked down the now grown-up kids whose mothers had been part of the double-the-meat experiment and measured their cortisol levels after a stressful public-speaking challenge. If their moms had eaten fewer than two daily servings of meat (fish included) while carrying them, they got relatively small surges of stress hormones from their adrenal glands.

The cortisol levels in those whose moms had eaten fourteen to sixteen servings a week rose 30 percent higher, and those whose moms had eaten the most meat—seventeen or more servings a week—had their cortisol levels jump more than 50 percent higher in response to the same imposed stress.4852

To the extent possible, we should try to reorient our lives to avoid major stressors and use exercise to work off what’s unavoidable. This can include yoga, walking, or resistance band stretches. Mindfulness techniques can be used to reduce stress and deal with cravings. To buffer the release of the stress hormone cortisol, we can reduce our intake of saturated fats and animal protein, and pile on the plants.

Obesity, like lung cancer, is not an equal-opportunity killer. Those living in poverty are significantly more likely to become obese.

Predatory industries such as fast food,4865 alcohol,4866 and tobacco have long targeted low-income neighborhoods and communities of color.4867 The soda industry appears to be no exception.

As one tobacco industry executive was recorded saying, “We don’t smoke that s***. We just sell it. We just reserve the right to smoke for the young, the poor, the black and the stupid.”4869

Population studies suggest the term beer belly is apropos, with drinking about a pint or more of beer a day associated with abdominal obesity. In some populations, drinking beer is associated with more sedentary lifestyles and poorer dietary choices,4874 though, so it’s hard to tease out cause and effect until you put it to the test.

Since the body has no capacity to store alcohol, it may temporarily switch from burning fat to burning alcohol to help clear it out of the system, leaving a small excess fat balance.

Thinking an aperitif might help patients with advanced cancer slow weight loss, researchers randomized subjects to a glass of wine a day, but it didn’t appear to make a difference. One study on wine and appetite showed a significant bump in caloric intake, but not for the reason the researchers were expecting.4877 When study participants were randomized to drink wine, beer, or soda with a meal, they ended up consuming more calories with the wine—but not because they ate more food. It was because they drank more wine. A quarter of the subjects drank the entire bottle, the “maximum allowed for ethical reasons.”4878

Although from a health standpoint “the safest level of drinking is none,”4880 inordinate weight gain may not be one of wine’s adverse effects.

People ate about two ounces of nuts every day for four days while their stools were collected. Those instructed to chew ten times per mouthful lost about 25 percent more fecal fat compared to those told to chew twenty-five times.

Same food, same amount of food, yet nearly two hundred fewer calories absorbed based on how they ate them.

For example, rolled oats have a significantly lower glycemic index than unsweetened instant oatmeal, which is also just straight oats but in thinner flakes,4892 and oat flakes cause lower blood sugar and insulin spikes than powdered oats.4893 The same single ingredient, oats, in different forms can have different effects.

After the instant oatmeal, the teens went on to eat 53 percent more than after eating the exact same number of calories of steel-cut oatmeal. The instant oatmeal group was snacking within an hour after the meal and went on to accumulate significantly more calories throughout the rest of the day.4894 Same type of food, but different form, yielding different effects.

Steel-cut oatmeal is considered a low-glycemic-index food, averaging under 55. The glycemic index of instant oatmeal is 79, making it a high-glycemic-index food, but not as bad as some breakfast cereals, which can get into the 80s or

In How Not to Die, I encouraged everyone to eat whole grains, but from an optimal weight-loss standpoint, that may be insufficient. Intact whole grains are superior to milled whole grains in the same way that whole grains are superior to refined grains.

Whole-wheat bread is better than white bread because it has more fiber to feed our good bacteria. If we just ate refined grains, we would starve our microbial selves. But fiber is pretty much all whole-wheat flour has to offer our colonic colleagues.

When whole grains are finely milled into flour, the rest of the nutrients are absorbed rapidly high up in the small intestine, leaving few leftovers. It still has the fiber, at least, so 100 percent whole-grain flour won’t leave our good gut bacteria completely starving, but they’ll certainly be left malnourished compared to if you had eaten an intac...

To claim “whole grain” on a label, the food just has to contain more than 51 percent whole-grain ingredients.4923

Even most “100 percent” whole-wheat flour these days starts out as white flour and then has some bran and germ added to approximate the proportions of the original grain.4924 Stone-ground flour, which really is just crushed grains, can be 100 percent whole grain though the cellular structure is still obliterated.

Nearly a half century ago, the dietary fiber hypothesis was proposed, suggesting that fiber was the reason that diets centered around whole plant foods were so protective against chronic disease.4925

Studies associating high fiber intake with lower risk of disease and death relate only to fiber from food intake rather than from fiber isolates or supplements.

Dietary fiber alone has certain benefits, but its primary role may be to encapsulate nutrients for special delivery to our gut microbiomes. If there’s one recurring theme in this book, it’s wall off your calories. Make sure as many of your calories as possible—your protein, your carbs, your fat—are encased in cell walls. Cell walls are made out of fiber, which acts as an indigestible physical barrier, so when you eat structurally intact plant foods, many of the calories remain trapped. Chew all you want—you’re still going to end up with calories completely surrounded by fiber, which then blunts the glycemic response, activates the ileal brake, and delivers sustenance to your friendly flora. That’s what nature intended to happen.

You can’t just sprinkle on the fiber. That’s not how fiber works. Fiber is the carrier. Fiber is the matrix. The word matrix comes from the Latin matricis, derived from mater, meaning mother.4930 We should strive to preserve the matrix (the blue pill, Neo) by choosing not just whole grains but intact grains.