Gary Taubes reveals the bad nutritional science of the last century—none more damaging or misguided than the “calories-in, calories-out” model of why we get fat—and the good science that has been ignored. He also answers the most persistent questions: Why are some people thin and others fat? What roles do exercise and genetics play in our weight? What foods should we eat, and what foods should we avoid?
Here are a few of the nuggets I pulled from my reading of Why We Get Fat.
* * *
A diet has to be something we can follow for life—a lifestyle program.
Low-fat diets fail to prevent heart disease, cancer, or anything else.
All these runners tended to get fatter with each passing year, even those who ran more than forty miles a week
The more energy you expend, the more you will increase the calories you consume.
Body types run in families. Genetics play a huge role in how your body is shaped.
If we restrict the amount of food an animal can eat (we can‘t just tell it to eat less, we have to give it no choice), not only does it get hungry, but it actually expends less energy. Its metabolic rate slows down.
Eating less and/or exercising more is not a viable treatment for obesity or being overweight and shouldn‘t be considered as such. It might have short-term effects but nothing that lasts more than a few months or a year. Eventually, our bodies compensate.
Men and women gain weight (and lose weight) differently which tells us that sex hormones play a role in regulating body fat.
If an animal that requires enormous gobs of fat for its winter fuel were to require excessive amounts of food to accumulate that fat, then one bad summer would have long ago wiped out the entire species.
Whatever makes us both fatter and heavier will also make us overeat.
A body will require excess calories to satisfy the demands of the growth—to build a bigger body—and it will figure out a way to get them, by increasing his appetite or decreasing his energy expenditure or both.
Fat is continuously flowing out of our fat cells and circulating around the body to be used for fuel and, if it‘s not used for fuel, returned to the fat cells. This goes on regardless of whether we‘ve recently eaten or exercised.
As these carbohydrates are digested, they appear in the bloodstream in the form of glucose, which is the sugar in blood sugar. (A carbohydrate called ―fructose, is a special case, and I‘ll discuss that later.) Cells throughout the body will burn this glucose for fuel and use it to replenish their backup fuel supplies, but they can‘t keep up with this rising tide of blood sugar unless they get help doing it.
Keep your blood sugar under control.
The more time passes after a meal, the more fat you will burn and the less glucose.
Another way to think of this is that your fat cells work as energy buffers. They provide a place to put the calories that you consumed during a meal and don‘t use immediately, and then they release the calories back into the circulation as you need them—just as your wallet
LPL is the enzyme that sticks out from the membranes of different cells and then pulls fat out of the bloodstream and into the cells.
While we‘re working out, LPL activity decreases on our fat cells and increases on muscle cells.
This prompts the release of fat from our fat tissue, so we can burn it in our muscle cells, which need the fuel.
Not only do our muscles crave protein after a workout to restock and rebuild, but our fat is actively restocking, too. The rest of the body tries to compensate for this energy drain, and our appetite increases.
When insulin levels go up, we store fat. When they come down, we mobilize the fat and use it for fuel.
Given the same food containing the same amount of carbohydrates, some people will secrete more insulin than others, and those who do are likely to put on more fat and have less energy.
Your muscle cells are likely to become resistant to insulin as you get older.
Not all foods that contain carbohydrates are equally fattening. This is a crucial point. The most fattening foods are the ones that have the greatest effect on our blood sugar and insulin levels. These are the concentrated sources of carbohydrates, and particularly those that we can digest quickly: anything made of refined flour (bread, cereals, and pasta), liquid carbohydrates (beers, fruit juices, and sodas), and starches (potatoes, rice, and corn). These foods flood the bloodstream quickly with glucose. Blood sugar shoots up; insulin shoots up. We get fatter.
The carbohydrates in leafy green vegetables like spinach and kale, on the other hand, are bound up with indigestible fiber and take much longer to be digested and enter our bloodstream.
Want to be as lean as you can be without compromising your health, you have to restrict carbohydrates and so keep your blood sugar and insulin levels low. The point to keep in mind is that you don‘t lose fat because you cut calories; you lose fat because you cut out the foods that make you fat—the carbohydrates.
Most quickly supply energy to the cells— easily digestible carbohydrates.
Even before we begin eating, insulin works to increase our feeling of hunger.
Brillat-Savarin memorably wrote, “Tell me what you eat and I shall tell you what you are.”
The typical Western diet—including cereal grains, dairy products, beverages, vegetable oils and dressings, and sugar and candy―would have contributed virtually none of the energy in the typical hunter-gatherer diet
There are genetic variations in fatness and leanness that are independent of diet.
If a diet requires that you semi-starve yourself, it will fail, because (1) your body adjusts to the caloric deficit by expending less energy, (2) you get hungry and stay hungry, and (3), a product of both of these, you get depressed, irritable, and chronically tired. Eventually you go back to eating what you always did—or become a binge eater—because you can‘t abide semi-starvation and its side effects indefinitely.
Insulin signals our kidneys to reabsorb sodium, which in turn causes water retention and raises blood pressure. When insulin levels drop, as they do when we restrict carbohydrates, our kidneys will excrete the sodium they‘ve been retaining and with it water.