Losing weight is so hard. Keeping it off is even harder. It turns out there are some strong biological reasons for this. The brain regulates all of our eating in 3 ways. 

1. Thanks to our ancestors, we have primitive pathways in the brain that drive our hunger and fullness to help us stay alive. 
2. The reward centers in the brain make eating enjoyable. 
3. Using the brain’s executive function, we consciously try to decide what, when, and how much to eat.

Metabolism Gone Haywire:“The disease of obesity causes overeating. Overeating does not cause the disease of obesity,” explains Gabriel Smolarz, MD, MS, FACE, Diplomate of the American Board of Obesity Medicine, medical director of obesity for Novo Nordisk. With the disease of obesity, the primary problem is a mix up of signals in the brain. The hunger and fullness cues have gone awry. The brain tells the person to eat more even though the energy supply or fat stores in the body are sufficient. Cognitive skills, based in executive function, like calorie counting and portion control strategies, are no match for the primitive brain in the presence of an imbalance in the hunger and fullness centers, so weight gain occurs, he adds.What’s worse, after weight loss, the body tries to return to its higher previous weight as a survival mechanism. The new, smaller body is more efficient and burns fewer calories. Hormones become unbalanced. Ghrelin, the hunger hormone, increases, telling you to eat more. And GLP-1 and other fullness hormones decrease, so you don’t get the message that it’s time to stop eating. All of this makes weight management a constant tug-of-war.There are Solutions:While losing weight and keeping it off are very difficult, they are not impossible tasks. First, keep in mind that small amounts of weight loss can have significant health benefits, such as decreased knee pain, lower blood pressure, less urinary incontinence, greater blood sugar control, and more. Losing as little as 5% of the starting weight -- say 10 pounds for someone weighing 200 pounds -– may improve health. Second, you don’t have to do it alone. Seek help from a registered dietitian nutritionist (RDN) to help you create a personalized food and lifestyle plan. If diet and exercise modifications don’t achieve meaningful weight loss, make an appointment with a medical provider for diagnostic testing, evaluation, and advice about medicine and surgical interventions. And keep trying. Most people with overweight and obesity try many times to lose weight alone. You can likely improve your results with professional help.You can find out more about the science of weight management at Truth About Weight and Rethink Obesity.By Jill Weisenberger, MS, RDN, CDCES, CHWC, FAND