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Five Reasons Why Sugar Contributes to Weight Gain

By Sachiko Giorgilli

Your body burns sugar to provide you with the energy necessary for life. Many foods are broken down into sugar in the body through the conversion of long and complex sugars called polysaccharides into short and simple sugars called monosaccharaides, such as glucose.

There are 5 main ways sugar can sabotage your body and cause fat storage.

1. Excess sugar causes insulin resistance

Eating excess sugar, especially fructose, raises insulin levels in the blood, which selectively deposits energy from foods into fat cells. It has been shown in controlled metabolic studies in humans that consuming large amounts of fructose can lead to insulin resistance and chronically elevated insulin levels, as well as problems with cholesterol, triglycerides and blood sugars.

2. Excess sugar causes leptin resistance

Leptin is a hormone that is secreted by fat cells. Leptin is referred to as the “satiety hormone” and tells the brain when you’re full and have had enough to eat. Excess fructose makes the brain leptin resistant, which means that the brain doesn’t “see” all the stored fat in the body and thinks that it is starving. This causes a powerful leptin-induced biochemical drive to keep eating even when you don’t need to.

3. Excess sugar induces ghrelin activation

Ghrelin is a hormone that is secreted primarily in the lining of the stomach.  Ghrelin is referred to as the “hunger hormone” and tells the brain when you’re hungry and haven’t had enough to eat. Excess fructose does not lower levels of the hunger hormone ghrelin, which in turn means that the brain continues to receive the message that you’re hungry. This increases overall food intake.

4. Sugar is addictive

Sugar, due to its powerful effects on the reward system in the brain, leads to classic signs of addiction comparable to drug abuse. This activates powerful reward-seeking behaviour that can drive overeating.

5. Sugar increases the production of the stress hormone ‘cortisol’

When your blood sugar levels are on a roller coaster ride, it induces the production of a stress hormone called cortisol.  Cortisol triggers the release of stored sugar from the liver bringing blood sugar levels back up. This reaction combined with the meal you eat after your appetite increase launches the entire “fat storage, metabolic decrease” process.

The more sugar you eat and the longer this process is allowed to continue, the more powerful it becomes.  Insulin and leptin resistance increase over time and the reward-seeking behaviour becomes stronger. In this way, sugar sets up an extremely powerful biochemical drive to make you eat more, burn less and put on weight.  Trying to exert willpower over this powerful drive can be next to impossible.

Note: This does NOT apply to fruits, which are real foods with fibre and a low energy density.  Fruits are a relatively minor source of fructose in the diet.

Sachiko Giorgilli – Nutritionist B.H.Sc Nutritional Medicine