You probably already know that sugar is bad for your health. Today we’re going to take a closer look at at one of the biggest risks of eating too much sugar: weight gain. We know that sugar contains calories, and excess calories are one of the reasons people gain weight. But sugar has a unique ability to cause weight gain in some other not-so-obvious ways. Much of this has to do with the fact that our bodies simply weren’t designed to handle the amount of sugar many people consume today.
This problem isn’t just for people who eat too many sweets — although people with certain DNA variants may need to be extra diligent about staying away from dessert-type foods. Even people who are trying to eat healthfully may find that sugar is lurking in many unlikely foods such as soups, salad dressings, and certain processed meats.
Fructose: the worst offender
One sugar in particular — fructose — is the type that is largely to blame for weight gain. Of course, fructose is found in high-fructose corn syrup, but regular table sugar is also to blame for our high fructose consumption. In fact, table sugar, or sucrose, is half fructose and half glucose, so even things that are labeled as “natural sugar” are often full of fructose.
Natural foods such as fruit and starchy vegetables also contain fructose. This doesn’t mean you should avoid fruits and vegetables, however. Fructose is present in relatively low quantities in these foods — and these foods also contain beneficial fiber, antioxidants, vitamins, and minerals. Most fruits and vegetables are low energy-dense foods, meaning they have very few calories per gram. So, you can eat larger servings of them without consuming high amounts of calories or sugar.
The main problem with fructose is that it’s also found in many processed foods and beverages, often in the form of high-fructose corn syrup or added sucrose. Beverages like soda contain large amounts of high-fructose corn syrup, and this ultra-sweet ingredient is added to many processed foods to improve their taste. Even foods that advertise containing only “natural sugar” are likely full of sucrose.
Even seemingly salty foods like crackers and marinara sauce may contain high-fructose corn syrup or sucrose, giving your body a huge hit of fructose without you even realizing it.
How the body processes fructose
Why is fructose worse than other types of sugar? The body can’t use fructose in its cells. So, the liver has to change it into glucose in order for it to be used for energy.
When the liver goes to work to process fructose, it releases fat into the blood. These fats — cholesterol and triglycerides — lead to an increased risk of heart disease and other health problems.
But the drawbacks don’t stop there. Fructose’s effects on the brain, hormones, and metabolism can have a strong effect on your ability to lose weight. Following are three ways sugar can have a negative effect on your weight.
1. Sugar turns off the body’s “fullness” hormone
Hormones dictate many of the body’s functions, including how easily we gain or lose weight. Leptin is one of the most important hormones in the body when it comes to fullness and hunger signals.
Leptin is found in the body’s fat cells. It sends signals to the brain about how much fat the body already has in its stores. High levels of leptin tell the brain that the body has enough fat. The brain gets the message that you don’t need to store up more fat; therefore, you don’t need to eat right now. So, your appetite will diminish and you’ll be less interested in eating. This is why high levels of leptin are desirable.
But leptin’s weight loss benefits don’t stop there. Higher levels of leptin also tell the body to rev up its metabolism and burn more fat.
In short, high leptin = fullness and fat burning power. It’s nature’s way of helping us balance our weight: when we have more body fat, burn it off. When we have less body fat, eat more and store the fat we have.
Unfortunately, a high-fructose diet interferes with leptin’s ability to do either of these things. Specifically, eating higher amounts of fructose leads to leptin resistance. This means that the brain no longer recognizes leptin and thinks the body doesn’t have enough, even if there’s already high amounts present. When this happens, the brain tells the body to eat more and burn less despite already being overweight or having eaten enough food.
Leptin resistance causes hunger even when we should feel full, and tells the body to hold onto excess fat, even when we don’t need it for survival.
2. Eating sugar just makes you hungrier
Several different studies have shown that consuming fructose can actually make a person want to eat more, regardless of how many calories they have consumed.
In one study, 20 people were given either a fructose or glucose drink with the same number of calories. Those who drank the fructose drink didn’t feel satisfied afterward and were still hungry. Those who drank the beverage containing glucose, which is recognized by the body and raises insulin levels, felt more satisfied and less interested in eating.
Another study had similar results, with brain imaging tests finding that people who consumed fructose had a greater desire for food and cravings for high-calorie foods than those who consumed glucose.
3. Sugar acts like an addictive substance in the brain
While saying sugar is “addictive” may seem far-fetched, there is medical evidence to back up this statement. One study states that sugar is as addictive as cocaine for lab rats. Consumption of sugar — especially high amounts — releases dopamine, a chemical that is associated with the reward center in the brain. Dopamine is activated when a person uses an addictive substance.
Most of the studies on sugar and addiction have found that larger amounts of sugar have this brain-altering effect. So, eating healthy foods that have small amounts of fructose, such as fruits, whole grains (without added sugar), and vegetables would not release dopamine and, therefore, would not cause cravings for more sugar.
Cutting back on sugar can seem like a difficult obstacle, especially in today’s world of sugar-laden processed foods. But at Garcia Weight Loss and Wellness Centers, our custom-tailored weight-loss plans are designed to address the factors that make weight loss difficult for you — whether that’s sugar cravings, hormone imbalances, leptin resistance, a slow metabolism, or other obstacles. Contact us for your no-cost consultation today!
Medically reviewed by Jay J. Garcia, MD on January 3, 2019