People struggle to keep their weight off… In fact, only 5% of people are able to maintain a 5% weight loss after 3 years (Crawford et al. Int. J. of Obesity. 24, 1107-10. 2000). I know… this is dismal.

Your body is very good at detecting an energy deficit. If your calories you burn exceed the calories you take in, your appetite increases (and remember I have told you this in my former blogs) this is due to ghrelin. An increase in appetite, results in an increase in your consumed calories, paired with a decrease in activity (your body learns to conserve its energy). And before you know it your calories in equal your calories out and you are back in energy balance.

As with everything, it is a double edge sword. Your body is not very good at detecting an energy surplus. If your calories in exceed your calories out, you do not get a decrease in appetite or an increase in activity. Control of your energy balance is unfortunately asymmetrical. Low energy diets and increased activity create an energy deficit. Your efficient signals will immediately drive you back to energy balance. In an energy surplus, with an energy dense diet and inactivity, there are inefficient signals and putting your health back into balance is much more difficult.

The big question is why can’t you eat just one? Well, palatable food disrupts our appetite regulation. High saturated fat/sugar diets increase neuropeptide Y (NPY). MPY is a protein that then releases in your brain causing you to seek out food. High fat diets increase the release of a protein called agouti-related peptide (ARP). ARP floods the brain and this triggers you to seek food. Wait it gets better. A lovely chemical in your body called cholecystokinin (CCK) releases and enters your brain when you have a nice moderate fat, moderate protein meal, triggering you to stop eating and decrease your food intake. But if you have the high fat burger and fries, this high meal/diet blunts the brain’s response to CCK. Therefore you do not decrease your food intake.

The answer to the question is yes, you are somewhat hardwired to eat that brownie. How about if you are obese, are you more likely to eat that brownie? The answer is… yes. Obese people don’t respond to satiety signals very well. After eating a moderate protein, moderate fat meal, the protein peptide YY (PYY) is released and travels to the brain. PYY helps to signal your brain to reduce its food intake as it now your body has been fed. However, obese individuals have lower levels of PYY, blunting their response to decrease food intake after they have eaten.

Our brains are magnificent, but they come with some hardwiring that does not make the weight loss game all that simple. Stay tuned for my next blog and I will let you know, how much food can resemble drug like qualities, hooking you and making you come back for more.