Health At Every Size: The Surprising Truth About Your Weight by Linda Bacon

study may not hold true if you alter other aspects of your diet not considered in that study. And lastly, we can’t ignore individual differences: Your particular genetic make-up may result in certain nutrients affecting you differently than that “average person” that the research describes. I encourage you to take the advice of the external authorities with a grain of salt. Use it to help you experiment with different foods, and then reap the benefits of trusting your body’s wisdom.
     
    With these cautions in mind, take a moment to reflect on what’s best for you. What’s your intent in learning about nutrition? Can you use your knowledge to help you tune in to your body, rather than creating food rules? Can you challenge yourself to be open-minded and accept the ambiguities? If you have any concerns about how you’re going to use the information that follows, again, I advise you to jump to the next chapter. You can always come back to this chapter another time.
     
    Now, let’s begin our journey into understanding the possible impact of nutrients on your setpoint.
     

Carbohydrates
     
    Some carbohydrates are more quickly digested and absorbed, contributing to a quick increase in blood sugar. Most of the increase in our calories over the past twenty years has come from those types of carbohydrates, called “high-glycemic carbohydrates.” 136 Simply put: We’re gobbling huge amounts of sugar and heaping plates of white rice, and we just can’t leave that bread plate alone.
     
    When consumed in excess, these foods cause a large spike in insulin production—the hormone that allows cells to use glucose for energy. Repeated large spikes can eventually overwhelm your cells, making them less sensitive to insulin. In scientific terms, this decreased sensitivity is called insulin resistance. (Genetic susceptibility also plays a large determining role.) Many scientists suspect that insulin resistance is the most important factor in determining susceptibility to weight gain. 137
     
    Insulin also helps other energy nutrients—like fat—get into cells. But unfortunately, the muscle cells get insulin resistant, not the fat cells, making fat storage easy at the same time that your hungry muscles are crying out for energy.
     
    Insulin resistance leads to weight gain as the glucose we can’t use gets converted into fat and stored. This extra fat tends to settle in the abdomen, where it is more volatile and more likely to contribute to diabetes, heart disease, and other illnesses. 138 Type 2 diabetes, the name given to the severe form of insulin resistance, is more common among heavier people, in part because of this process: Insulin resistance drives weight gain. Many large people have at least a moderate degree of insulin resistance, even if it’s not severe enough to be labeled diabetes.
     
    But insulin does much more than enable your cells to use glucose for energy or to store fat. It also signals your hypothalamus to send out less neuropeptide Y. Reducing the supply of this neurotransmitter turns down your appetite switch while increasing your metabolism. Insulin also stimulates the release of leptin, which amplifies this effect. That’s why normal insulin production and use is so important for weight regulation.
     
    Avoiding insulin production isn’t helpful; it’s the insulin spikes that are disconcerting. While most people put the blame for insulin spikes on excess consumption of sugar, it turns out that refined grains, like those found in many breads, cereals, and rices, are equally at fault. Ironically, the U.S. government’s attempt to deal with obesity by encouraging people to build their diets on the old Food Guide Pyramid’s base of “bread, cereal, rice, and pasta,” seems to have backfired. (Note that the pyramid comes from the U.S. Department of Agriculture . A primary purpose of this agency is to promote agriculture—and its recommendations are designed, in part, to support agribusiness.