Carbohydrates are very important to living beings. So, why is sugar so bad for you? You need carbohydrates in your diet to provide energy to each cell, to supply your brain with glucose, and to furnish fuel for muscles and organs. All your DNA and RNA molecules have a sugar molecule in them. In fact, if you don’t eat enough carbohydrates, your body breaks down muscle tissue to make some!
What’s with all the low-carb buzz?
The physiological response you get from eating any carbohydrate depends on the type of carb and the amount that you eat. Do it right and you have a normal, healthy response. Do it wrong and the chemistry created in your body makes you fat, sick, and addicted.
Here are the basic steps of what happens to the carbohydrates that you eat:
Your digestive system breaks down carbohydrates (first in your mouth with saliva and chewing, and then from digestive enzymes in your small intestine) into smaller bits of carbohydrate known as monosaccharides.
Your liver absorbs the monosaccharides and, like a dispatcher, sends them out to do various important jobs — feed the brain, make cells to do their thing, and fill up your muscles and organs with fuel.
After these jobs are finished, your body promptly packages up and stores any leftover carbs as body fat.
The problem with sugar is that it’s not only high in calories but also virtually nutrient- and fiber-free. When you eat a lot of sugar (without fiber, protein, or fat), far too much sugar enters the bloodstream at one time. This creates a chemical emergency in your body, which responds to the assault by prompting the pancreas to release a large dose of insulin to control the sugar levels.
How does this connect to insulin? Diabetes is one of the biggest threats to modern human health. With high sugar intake, low amounts of exercise, and too many calories overall (which unfortunately describes most of America these days), the body is forced to produce more and more insulin, a hormone that’s essential for preventing a dangerous buildup of sugar in your bloodstream but that, at high levels, can cause problems.
High insulin levels cause you to store fat and crave more food. This cycle continues over the years, and as you gain weight, your body becomes less and less sensitive to insulin, and it craves more and more sugar. The end result is obesity and insulin resistance, which lead to diabetes.
The most important source of fuel for your body is glucose, which enters the bloodstream after you eat. Glucose then travels throughout your bloodstream and is used by every cell in your body for energy.
The pancreas, an organ located behind your stomach, is in charge of releasing hormones that make your body either store or release calories. One of those hormones is insulin.
Insulin “unlocks” your cells to allow the sugar circulating in the blood to enter cells, where it can be turned into energy. After you eat a meal, your pancreas senses a rise in blood sugar levels and releases the insulin needed to move sugar from your blood into your cells. When you eat too many carbohydrates, your pancreas is forced to secrete a lot of insulin to manage the sugar.
Insulin generally does an adequate job of shuttling all that sugar to the right places (including turning all the extra sugar into fat), but regularly having high insulin levels causes several serious problems:
High insulin levels decrease your ability to burn body fat for fuel.
Over time your body becomes less sensitive to all the extra insulin, and it requires more and more of it to control blood sugar levels. This is called insulin resistance, and it inevitably leads to type 2 diabetes.
High insulin levels lower blood sugar levels — that’s insulin’s job, after all. Too much insulin lowers blood sugar levels too far. Sugar crash! This causes more cravings.
High insulin levels make you sleepy and sluggish.