In his book The Obesity Code, Dr. Jason Fung refers to “the insidious snack” in chapter 11. As a nephrologist (kidney doctor), most of Dr. Fung’s patients are diabetics and usually obese, which sparked his research and subsequent books on the subjects of obesity and diabetes. After indepth research and years of treating his patients, Dr. Fung has come to a few conclusions: the major cause of obesity, diabetes and weight gain is insulin resistance and the two driving forces behind insulin resistance are diet and meal timing.
Insulin resistance is what happens when we always have insulin (a storage hormone) in our blood stream. We eat something; our digestive tract turns the food into glucose, amino acids and fatty acids which flood our blood stream and our body releases insulin to put the glucose into storage as fat. When we are insulin resistant, our cells are resistant to letting in the insulin with its attached glucose for storage, so our body has to release more insulin to do the same job as before. The more insulin we have in our blood stream, the more we need to release to keep doing the same job and the longer it takes to clear the glucose and insulin from our blood. Say you are sweeping up a handful of sand from the floor. If your broom has tight bristles, it only takes a few sweeps to get up the sand, but if your broom has gaps in the bristles or they are frayed and loose, it will take twice as many sweeps to get up that same handful of sand. It takes longer and isn’t as effective, so you keep sweeping up what was missed. This is what happens with glucose and insulin when we are insulin resistant.
Insulin resistance happens over time and it isn’t something that ‘happens’ to us like an illness or an accident: we make ourselves insulin resistant through our food choices and eating habits. In the last fifty-plus years, we’ve been encouraged to eat more ‘healthy whole grains’ and processed foods and we’ve been encouraged to eat more often. These are the two chief causes of insulin resistance and its metabolic companions, obesity and diabetes. Refined carbohydrates such as bread, pasta, cereals and other grains, along with sugar, are the major offenders when it comes to blood sugar and insulin. Eating a bagel for breakfast will cause a bigger spike in our blood glucose which means more insulin is released into our blood stream than if we had eaten scrambled eggs instead. That means it takes longer to clear the glucose and insulin and return to fasting (non-eating) levels.
Refined carbohydrates aren’t a new invention but snack foods are. In the past, snacking between meals was discouraged and there certainly wasn’t a class of food made just for snacking! In the late 1970’s, food companies started encouraging people (and kids especially) to eat between meals. Snack cakes, snack crackers, snack packs of pudding and other snack foods fill up grocery store aisles and most gas station mini-marts are dedicated almost entirely to these snack items. Most of these foods are sugar-rich or made up of refined carbohydrates but what’s worse is that we are encouraged to eat them at any time of day!
Some health care professionals promote eating every two to three hours to “boost our metabolism.” In short, eating more often supposedly ‘revs up’ our metabolism so we lose more weight. So, ‘Eat More, Lose Weight’? Not likely! While eating briefly speeds up our metabolism to digest the food we ate, the increase is negligible compared to the extra calories and the insulin resistance which results from the continued snacking! All those times we told ourselves that this one little snack won’t hurt us? Wrong!
Remember when I said insulin is a storage hormone? That means you can’t burn fat (lose weight) while insulin is in the blood and every time we eat, we release insulin so the insulin never has a chance to clear because we are always eating! When we are insulin resistant, it takes even longer to clear, so if we eat every two to three hours, when are we able to burn fat? That would be never! So we keep on gaining weight and becoming more and more insulin resistant until we become diabetic and our metabolic problems continue to multiply.
Before the obesity epidemic arose in the early 1980’s, people ate refined carbs and cereals but other than lower sugar consumption, this idea of snacking is the biggest change in eating habits. People ate breakfast, lunch and dinner and nothing in between. That meant that for several hours in between meals and during the night, insulin wasn’t circulating in their blood stream. They ate meals, including refined carbs, and then they stopped eating for hours until the next meal. That meant insulin was released, cleared the glucose and went away until the next meal. They didn’t become insulin resistant because they weren’t constantly exposed to insulin even when they did eat sugar or refined carbs.
In several of his books, including The Obesity Code and The Diabetes Code, Dr. Fung recommends fasting to counteract insulin resistance. He also deals with some of the misconceptions that come with the idea of going without food for a prolonged period of time in his book The Complete Guide to Fasting. This doesn’t mean that you have to starve yourself for days or weeks to lose weight. It does mean that we should stop eating between meals and if you aren’t hungry at breakfast or lunchtime, then don’t eat. Skipping a few meals if we aren’t hungry or are too busy to eat isn’t going to hurt us and will improve our insulin resistance and for goodness’ sake, put down that insidious snack!