As a young thin man I knew exactly how to lose weight. I knew that all anyone had to do to lose weight was to eat less and exercise more. It was simple math. One needed only to burn more calories than one took in.
My experience as a doctor has taught me that weight loss is not simple math. Some of my patients would eat less, exercise more and gain weight. Impossible I thought. They must be cheating on their diet. But highly motivated, disciplined, sincere patients would not lose an ounce. Now I know that whether we gain or lose weight is largely regulated by our hormones. Weight loss is nearly impossible short of starvation when our hormones are set to hold weight on.
There are seven hormone categories that need to be regulated to allow weight loss. They are insulin, cortisol, male hormones, estrogens, thyroxine, epinephrine and insulin growth factor. This article will discuss the first two hormones. The others will be discussed in future articles.
Insulin is the most important hormone in weight control. Insulin is released from the pancreas after eating. Blood insulin levels are highest in the 2 hours after a meal. Blood insulin levels are especially high after a meal high in sugar or starchy (high carbohydrate) foods such as pasta, bread, rice or potatoes. Insulin acts like a key that opens the door in our cells that lets sugar in. Without insulin sugar cannot get into cells and stays in the blood. The pancreas of people with type 1 diabetics cannot make insulin. Without insulin injections they slowly starve to death even though their blood in full of sugar.
Insulin also stimulates the conversion of sugar into fat. Insulin helps us to store energy Insulin stimulates the conversion of extra calories into fat for a rainy day. Sweet or starchy foods cause insulin levels to rise more that fats or protein. Sweet or starchy foods are easily converted into fat. Insulin is a powerful weight gain hormone.
Some people are extremely efficient at storing fat. Their ancestors survived famines and passed their thrifty genes on to them. In today’s world of calorie/carbohydrate excess they are a disadvantage. Low carbohydrate diets (such as Atkins) are effective for most people because insulin levels remain low. By avoiding sugars and starches, insulin levels remain low and the signal to store calories is weak. The body breaks down fat to keep energy levels up. Low carbohydrate diets mimic the caveman diet of meat and plants (vegetables). Many of us are still cavemen on a cellular level.
Low carbohydrate diets are not for everybody. People with poor kidney function can get sick from to much protein in their diet. Others may not need to completely avoid carbohydrates to lose weight. For most people a low-carb diet will help them lose weight.
Cortisol is another important weight gain hormone. Cortisol is released from the cortex (outside edge) of the adrenal gland. The adrenal gland sits on top of the kidneys and is the location where many hormones are produced. Cortisol is a stress hormone and is released during stress. Cortisol causes blood sugars to rise among other effects. This helps us to either fight or to run away from the stress. This is great if the stressful event is a saber tooth lion, but is not very helpful if the stressful event is a difficult customer or our boss. Without some kind of exercise the increased blood sugars are not used. The body senses the increased blood sugar and releases insulin. The insulin clears the sugar from the blood by converting it into fat. In other words, stress can make you fat. No wonder we feel better after a stressful event if we can “walk it off”.
Regular exercise can help us become more resilient to the effects of stress.