Every time you consume sugar (especially by itself) you are training your body to "lock in" and store body fat. Let me explain.
You have two important hormones that play a role in fat release in your body, insulin and glucagon. You've probably heard of insulin in relation to diabetes as diabetes is a blood sugar irregularity and insulin is the hormone that regulates sugar transport storage.
When you eat the "good sugars" (a.k.a. complex carbohydrates, like whole grain breads, whole grain pastas, oatmeal, potatoes, yams, etc.), you have consumed long chains of sugars that are linked together. These long chains of sugars are the reason these carbohydrates are termed "complex carbohydrates". When complex carbohydrates pass through your digestive tract these chains are slowly broken apart sending a slow trickle of sugar into the bloodstream.
Glucagon is an energy-releasing hormone. It's job is to free up body fat for you to burn as fuel. The job of the pancreas is to balance your insulin and your glucagon. When the pancreas is called on to produce more insulin because of blood sugar elevation it will back off production of glucagon. If you don't produce glucagon, you don't have fat release. This is why sugar poses a major obstacle for fat release. Think of glucagon as the key to unlock the fat from your cells and into the bloodstream to be burned by your muscles.
Simple sugars, (a.k.a. donuts, cookies, cakes etc.), are exactly that, they are simple and thus are absorbed into the bloodstream all at once which is why you get a momentary spike in your blood sugar. There is no work for the digestive system to do in order to break down a simple sugar. Simple sugars signal the pancreas to produce more insulin.
Insulin helps produce energy in individuals with normal insulin regulation. When called upon it's usually due to an elevation of blood sugar. Your blood sugar levels directly determine the amount of insulin you produce. When you experience a rush of energy from simple sugars and you have that momentary spike in your energy levels, your pancreas overreacts to this spike and sends out more insulin that is required. This is where you will receive a perceived rush of energy. As you well know this sugar rush is short term because as soon as the body works to get that blood sugar level down, it leaves you feeling tired and cranky. This sends a message to your brain to go eat more sugar, thus when you eat sugar you crave sugar. This is a dangerous cycle that keeps you with stored fat on your body.
In a nutshell:
complex carbohydrates = good= slow release of energy into the bloodstream
simple carbohydrates = bad sugar spike = no fat release because glucagon is not released
Here are some synonyms for sugar you need to be on the lookout for. Please keep in mind, however, that not all of them are bad for you. Just click on any of the highlighted links below to find out more:
Be aware that food manufacturers add sugar in foods that you'd never expect.