Why We Get Fat: And What to Do About It

America — and much of the rest of the developed world — has a fat problem.

Being fat, of course, is more than how we look; obesity is arguably the one true cause of our most prevalent and crippling modern diseases. Obesity correlates to increased risk of heart disease, stroke, cancer, hypertension, diabetes, gastrointestinal disorders, Alzheimers and more. When we are overweight, we have less energy and are limited in activities.

Modern health professionals emphasize several reasons for the obesity epidemic; they claim that we are sedentary; that we eat too many fattening junk foods. These make intuitive sense, at first glance.

Ask most people why we get fat and they will answer with something along the lines of, “because we eat more calories than we consume”. However, in Why We Get Fat, Gary Taubes argues that the scientific literature actually shows that we are sedentary and crave junk foods because we are fat. In other words, the medical establishment has the cause and effect reversed.

But if lack of exercise and Twinkies aren’t making us fat, then what is? And what can we do about it?

I will caution you; as you read some of what follows, it will feel … wrong, at least at first. Why? Because many of us have heard the conventional wisdom repeated so often and so forcefully for most of our lives, that we long ago stopped questioning it. The discomfort of cognitive dissonance is real, but I encourage you to read with an open mind.

Here are my key takeaways:

• For some people, eating an excess of carbohydrates (and not merely calories) biologically “programs” you to be fat. In other words, being overweight has little to do with how many calories you burn or how many calories you take in. It’s the nature of these calories — the ratio of carbohydrates to protein to fat — which makes all the difference.

  The bottom line? Starting today, reducing carbohydrates — particularly those which are easy to digest, including starches and liquid carbohydrates like beer, soda and even fruit juices — is the single most important thing you can do to lose weight and keep it off. In order to avoid the unpleasant effects of calorie deprivation, it’s important that you eat adequate quantities of protein and fat.

• When insulin levels are elevated, we store dietary calories as fat in our fat tissues; when insulin levels fall, our bodies burn fat for fuel. The very short version of a very complex process goes something like this:

  Insulin does many things in the human body, but one of its most important roles is to keep blood sugar under control. (Too much or too little, and you’ll have major issues.)

  Insulin secretes primarily in response to the carbohydrates in your food; the more insulin we have circulating in our bloodstream, the more actively our bodies are storing calories — any calories — into fat tissues. Conversely, when insulin drops, our bodies burn fat. (Hence, we sleep peacefully despite not having eaten for hours.)

  As insulin levels remain elevated for longer periods of time (again, in response to carbohydrates eaten), our bodies are unable to use stored fat calories, so we feel hungry; kicking off a vicious cycle in which we eat more despite having “plenty” of spare calories to burn.

  In time, elevated insulin levels lead to insulin-resistance (a precursor to diabetes), meaning that your body requires more insulin and thus amplifying the fat storage mechanism.

• Our bodies are tightly regulated by complex hormonal systems, influenced by a variety of genetic factors. For example, no one disputes that genetics control how tall a person gets. So it is with the endocrine systems which drive fat storage; this is primarily why two people can eat an identical diet and get wildly different results. Men and women fatten in different areas and in response to different events (i.e., pregnancy); animals tend to maintain their fat stores both in times of abundance and famine.

  Problems arise when the body’s self-regulation goes haywire. In one experiment, researchers removed rats’ ovaries; the rats, post-surgery, were given the same amount of food yet they fattened dramatically and became sedentary. Their bodies were shunting calories away from their bloodstream and into their fat stores, even as the rats were fundamentally malnourished. Researchers also used to insert a needle into the hypothalamus of rats to induce voracious eating; not coincidentally, the hypothalamus regulates hormone levels.

  In other words, fat tissues do not react to the amount of calories we eat, rather they react to [normal, or abnormal] hormonal signals. Conversely, lean people are biologically driven by these same systems to burn off excess fuels.

• There were many fat, unhealthy populations which before the advent of fried, fast foods. The Pima indians of the late nineteenth and early twentieth centuries, for example, were hard-working, poor and underfed; yet they were predominantly obese. Numerous other indigenous populations throughout the world show similar traits.

  When did these populations become obese? As soon as they gained access to modern agricultural methods including, most notably, sugar. (Arguably, the human body did not evolve to eat sugars of any kind approaching the quantities that we eat today.)

• Conversely, there have been many thin and fit populations which eat lots of foods which are high in fat. For example, our hunter-gatherer ancestors, or more recently, the Inuit (before they began trading with Europeans for sugar), Kenyan tribes and South Pacific islanders, to name a few.
• Since the 1970s, in spite of the proliferation of low-fat diets and foods, heart disease has become increasingly rampant. The vast majority of research simply does not support the notion that low-fat diets reduce heart disease. Triglycerides — an important predictor of heart disease — correlate to carbohydrate consumption. HDL — another important predictor — is inversely correlated to the amount of carbs we eat. Eating animal fat actually improves overall measures of a cholesterol panel, while a diet rich in carbs will harm it.
• Study after study demonstrates that a majority of low-calorie dieters achieve mediocre weight loss results, if they keep it off at all. A 2007 Tufts University reviewed all relevant diet trials conducted since 1980; it concluded that most participants lose 9-10 pounds within six months and that after a year, much of the initial loss was regained. This is because …
• Trying to restrict all calories is a recipe for failure because it causes us to become lethargic, reduces our metabolism and is just not a sustainable approach. Numerous human and animal studies demonstrate that living creatures who deprive themselves of calories — or whom are forcefully deprived by war, famine or scientific experiments — tend to be hungry, cranky and they expend less energy. Even if you are able to knuckle through such discomfort for a short time, what are the odds that you’ll be able to keep it up for years?

  The energy we consume and the energy we expend are dependent variables; not independent, as we have been led to assume. We are hard-pressed to adjust one without causing a compensatory reaction in the other.

  The key, once again, is to reduce carbs but eat adequate quantities of other foods which are high in protein and fat.

• Exercise is good for many things, but weight loss may not be one of them. Of course, exercising does burn calories; it does build lean muscle and it does raise your metabolism. But importantly, all of these things will also make you hungrier. So in effect, the advice which is so commonly prescribed to help us lose weight will forcefully induce us to gain it.

  Besides, in terms of calories, the benefits of exercise are modest any how. An adult man can expect to burn 3 calories climbing a single flight of stairs, but he’ll have to climb 30 flights of stairs to work off a single slice of bread.

  Replacing five pounds of fat with five pounds of muscle will cause us to burn a whopping twelve extra calories per day.

• But thin does not necessarily mean healthy, either. Some lean people may nevertheless have metabolic syndrome; having visceral fat clustered around their organs which is again, an effect of excess carbohydrates.
• It is actually possible to get most essential vitamins from animal sources. In particular, meats contain essential fats, all amino acids as well as vitamins A, E,B and D.
• For some, it is enough to reduce consumption of the most offensive carbs; for others, much stricter measures may be necessary. Once again, our bodies differ.

I’d like to wind these notes up with a personal experience.

I’ve been overweight to some extent for most of my adult life. I’ve weighed nearly 300 pounds at one point, but in recent years I’ve hovered around 260.

Well, in the beginning of 2016, I reluctantly went on a diet for the first time in my life to help me get chronic acid reflux under control. (If you’re interested, you can read more about that here.) Remarkably, I lost twenty pounds in just over two months. How?

Explaining this rapid weight loss (and permanent, I might add; I haven’t put it back on) with the calories-in/calories-out model, I would have had to burn 70,000 calories more than I ate over two months; running an average deficit of over 1,100 calories per day!

I have always wondered about this result; Why We Get Fat explains it in clear terms. I wasn’t hitting the treadmill for two additional hours each day or starving myself; I was primarily cutting out the carbohydrate-rich foods (namely, soda and alcohol, which are implicated in reflux) that I loved.

My reflux cleared up to significant extent, so I slowly began re-introducing those foods to my diet. Mercifully, I hadn’t gained any weight back, but I stopped losing it too.

Having finished this book about a week ago, I’ve begun to reduce my intake of carbs again. It’s hard at first; sugar is addictive, after all. But I find that it’s not so difficult when I can replace these carbs with other foods I love, like hard-boiled eggs or even bacon. And now, a week later, I realize that I’m not nearly as hungry and I’m already down another three pounds.

As I said in the beginning, if you or someone you love has ever struggled with weight loss, I can’t recommend this book highly enough.

Updated on 9/15/2016 to add: On this very topic, here is an important, recently published article which looks at how the sugar industry funded research to deflect blame toward fat, a move which would shape national focus for decades to come; it’s worth a read.