What’s So Bad About Sugar?
You’ve probably heard this a million times before… but it’s worth repeating. Added sugars (like sucrose and high fructose corn syrup) contain a whole bunch of calories with NO essential nutrients. For this reason, they are called “empty” calories. There are no proteins, essential fats, vitamins or minerals in sugar… just pure energy.
When people eat up to 10-20% of calories as sugar (or more), this can become a major problem and contribute to nutrient deficiencies. Sugar is also very bad for the teeth, because it provides easily digestible energy for the bad bacteria in the mouth.
What is Included in the Meaning of Sugar?
- Table sugar made from beets or sugar cane.
- High-fructose corn syrup made from corn—the kind that’s in soda pop & most processed foods.
- Honey made from bees.
- Agave made from succulents.
- Maple syrup made from the sap of maple trees.
- Fruit juice of any kind–even the 100% real stuff. Yes, that includes orange juice.
They are all the same. They are sucrose—which is 1/2 fructose, and 1/2 glucose.
Glucose is good. It’s the energy of life; all carbohydrates are glucose—the starches, the pastas, the beans & legumes. It gives us energy and can be used by every cell and every organ in our body.
Fructose, on the other hand, is bad news once it’s separated from the fibre of whole fruit or plants. It’s completely different from glucose.
Listen closely: fructose is metabolized ONLY in the liver and it’s metabolized just like fat. No other organ in the body can metabolize it—and instead of generating energy—it ends up generating FAT. That’s right, the liver turns fructose straight into fat cells and when your liver generates fat, it becomes insulin-resistant.
What’s so bad about insulin-resistance?
When the liver becomes insulin-resistant—it drives up your insulin levels, so instead of burning the energy from the food you are eating, you store even more of it as fat in your cells, driving you to eat even more.
As Lustig explains it, sugar/soda pop/juice/dessert-eating Canadians are releasing about twice the insulin than they were 25 years ago and all that extra insulin is driving the food we eat to get stored as more fat, which makes us even more insulin-resistant.
“The higher the insulin level goes, the more food you want to eat & the less well your brain is able to get the signal from your gut that you’re full. Leptin, the satiety hormone, is effectively disabled in the presence of insulin-resistance, and you can blame that on all the sugar/fructose that the liver turned into fat.”
Not all calories are created equal.
Different foods can have different effects on our brains and the hormones that control food intake. Studies show that fructose doesn’t have the same kind of effect on satiety as glucose. In one study, people drank either a fructose-sweetened drink or a glucose-sweetened drink. Afterwards, the fructose drinkers had much less activity in the satiety centers of the brain and felt hungrier. There is also a study where fructose didn’t lower the hunger hormone ghrelin nearly as much as glucose did. Over time, because the calories from sugar aren’t as fulfilling, this can translate into an increased calorie intake.