Scientists have found that the key part of the brain that is focused on stopping the body from acting on impulse (which includes gorging), does not work as effectively in overweight and obese people.
A study led by scientists in Yale University found that when glucose levels fell, it led to a loss of self-control in the brain which ultimately led to craving ‘treat’ foods. In those who are overweight, that craving came as soon as there was a slight drop in the glucose levels, and so carbohydrate rich foods were sought more quickly.
Glucose is needed to fuel the brain. That fuel is gained from carbohydrate rich foods that can be healthy, but often come in the form of cakes, biscuits and crisps. To ensure the brain stays fuelled, it would mean maintaining those glucose levels; in order to stay slimmer, we need to snack on more vegetables and fruit rather than taking a biscuit with sugary tea for our mid-morning snack.
The study had volunteers hooked up to intravenous drips and manipulated their glucose levels. Whilst this was happening, they underwent Functional Magnetic Resonance Imaging Scans of their brains. They were shown both high and low calorie foods as well as non-edible items.
The scans showed that when glucose levels were low, two ‘reward’ regions in the brain induced a desire to eat. The ‘sensible’ part of the brain which stops people acting on impulse lost the ability to rein back the urgent ‘eat’ signals. This ability was at its lowest level when overweight volunteers were shown high-calorie foods.
Ultimately, if you are trying to maintain your weight, or to lose weight, the brain needs fed. Keep glucose levels up by eating healthy carbs and don’t let them drop to a level where you’re craving chocolate.