People looking at wheat-free diets, for multiple reasons, might be interested in whether the diet will cause them to lose or gain weight. As with most things with the body, the weight-gain picture is way more complex than just being the result of an abundance of insulin.
Keeping glucose levels down allows insulin levels to stay low so the body dumps energy from the fat cells. But insulin levels can also rise in the absence of higher glucose levels. The culprit: a hormone called leptin.
Leptin is actually made by fat cells, a fact discovered only recently. Fat cells don't just lie around storing energy. The more fat cells you have, the more leptin is produced. Leptin acts as a messenger to the brain (mainly to the hypothalamus).
The brain isn't able to monitor the body's energy balance, so it relies on leptin to act as its man in the field, so to speak. For a normal-weight person, the process goes as follows:
The person overeats and body fat levels go up. Consequently, leptin levels go up.
The brain gets the message and tells the body to reduce food intake and increase energy levels.
Body fat levels go down, leptin levels go down, and the brain tells the body to increase food intake and reduce energy levels.
With this system, the body maintains a stable weight, give or take a few pounds. (This consistency is also known as homeostasis.) But the situation is different for people who are overweight or obese:
The person overeats and body fat levels go up. Consequently, leptin levels go up.
The brain doesn't tell the body to reduce food intake. It thinks the person is still hungry, so she eats more and more and energy levels stay down.
In much the same way that the cells become resistant to insulin, the brain becomes resistant to leptin; more and more leptin is necessary to get the message across. Unfortunately, whereas the pancreas can create more insulin, you don't have an organ to produce more leptin.
Only the fat cells can make it. Research has shown that this malady called leptin resistance may actually precede insulin resistance and weight gain itself.
Inflammation causes the brain to be less receptive to the leptin signaling. Inflammation is a very general term, however, so here are some of its various causes as it relates to leptin resistance:
Wheat, other grains, sugar, and refined food: These foods, all of them carbohydrates, increase triglycerides. High triglycerides prevent leptin from passing through the blood-brain barrier. The leptin that does get through meets a weakened response due to the high fructose intake. (These foods can also lead to a condition called leaky gut.)
Fatty acid imbalances: You need an appropriate ratio of omega-6 fatty acids to omega-3 fatty acids in your diet. A ratio of 1:1 is most desirable, but the average American's ratio is closer to 15:1 or even 20:1. The inflammation caused by this imbalance extends to the brain, disrupting leptin's message.
Stress and poor sleep: Lack of sleep increases the stress hormone cortisol, which unleashes myriad negative effects. Stress and poor sleep can also work against your gut's stores of good bacteria.
Gut infections, food toxins, environmental toxins, and nutrient deficiencies: All these factors contribute to leaky gut, which leads to inflammation and leptin resistance.