CHAPTER 7

Sweetness is Our Weakness

Regularly flooding your bloodstream with sugar takes a serious toll

PART 1 You Might Be Hooked

Sugar prompts the release of dopamine in the brain, and the resulting feelings of well-being are undeniable. The withdrawal of sugar from the diet has been shown in studies to trigger a chain of events very similar to that of opiate-drug withdrawal. READ MORE

Researchers at Princeton University who wanted to find out more about sugar's addictive properties designed a study similar to those used to gauge the effects of illicit drugs. When lab rats were given a sugary solution, the brain chemical dopamine was released into the nucleus accumbens in the brain, just as it is when a person takes heroin. The rats responded by bingeing on the sugar whenever it was available, which caused large surges of dopamine to be released, just as drug users binge to get a chemical high. The researchers wondered whether the rats would have withdrawal symptoms, which would indicate a true addiction. They blocked the receptors for dopamine in the test rats' brains so they would not feel the dopamine rush. This caused anxiety and a drop in dopamine level—signs of withdrawal. The process isn't perfectly analogous to the addiction mechanism in humans, but these rats were definitely hooked on sugar. Researchers hope that the findings might lead to new methods of diagnosing and treating binge-eating disorders or bulimia. LESS

PART 2 Insulin in Action

The hormone insulin is secreted by the pancreas. Its job is to control your blood sugar levels. Your glucose levels rise when you eat carbohydrates, and a little less dramatically in response to the protein and fat you eat. Insulin signals cells to burn glucose for energy, or to store it for later use. Some is stored as fat in fat cells, and that begins a process that can make some of us pack away too much fat. READ MORE

Insulin is created by the pancreas and secreted into the bloodstream when you eat. Through several mechanisms, it signals the storage or use of energy from our food. During and after a meal containing a lot of sugar, insulin floods the bloodstream to direct traffic. The hormone controls an enzyme called lipoprotein lipase, or LPL, which pulls fatty acids from the bloodstream into cells for storage. When LPL pulls fatty acids into a fat cell, three fatty acids join a glycerol molecule to form a triglyceride. Triglycerides stay stored in fat cells, as they are too big to pass through the fat cell membrane. Another enzyme, called hormone sensitive lipase (HSL) can dismantle triglycerides in the fat cell so that their individual fatty acids can be released from the cell into the bloodstream. Insulin is a key player in how much of our energy intake is burned immediately, sent to muscle or liver cells, or stored as fat. LESS

PART 3 How to Break the Cycle

It Adds Up

45.3 Pounds of added sugars...

Some people are genetically predisposed to efficiently managing their blood glucose without packing on fat. Lucky them. If you are overweight, cutting your consumption of sugar can be a good way to jump start your wellness mission. Many nutritionists agree that a diet built on protein, vitamin-rich vegetables and (yes) the right kinds of fats could help millions of overweight and obese adults. READ MORE

There is no consensus on the perfect diet to help everyone establish and maintain a normal weight and vigorous health. However, not many nutritionists would encourage someone who is overweight to continue eating high-sugar foods. “A major culprit for the obesity epidemic is the high consumption of sugar-dense soft drinks,” says Dr. Philipp Scherer, director of the Touchstone Diabetes Center at the University of Texas Southwestern Medical Center. “It's the Big Gulp!” Indeed, the average American takes in more than double the amount of calories from sweetened soft drinks as he or she would have in 1977. Cutting back on sweet desserts and drinks is a good start. Also, scan nutrition labels for ingredients ending in the suffix “ose,” such as glucose, sucrose, fructose, maltose, dextrose. Those are sugars. If they appear among the first few ingredients in packaged foods, look for a product that has sugar farther down the list. Ingredients are listed in order of amount. LESS