Why is Weight Loss So Hard to Maintain?

So, you have worked hard to lose weight and are feeling really good. Why does it feel like you take your eye off the ball for a second and the weight starts creeping back? The reality is it isn’t your fault or that you suddenly are doing everything wrong. There is a physiologic process going on! The body very tightly regulates energy intake and output, and the body very much likes to have these be equal (energy homeostasis). If you have lost weight (decreased energy in), your body thinks it is starving and wants the energy you had stored in your adipose tissue (fat cells) back.

What happens? Is it your metabolism? Is it hormonal? The answer is yes to both. Research studies have shown pretty conclusively that the body undergoes Metabolic Adaptation and your energy expenditure (calories burned) goes down. It would make sense that if you have lost a lot of weight, your energy expenditure would go down more than if you lost less but, that doesn’t seem to be the case in studies, it can decrease the same with either. What isn’t known completely is how long does your EE stay down? A study on Biggest Loser participants showed that 6 years after the show, despite having significant weight recurrence, their resting energy expenditure did not go back to baseline, where it was before weight loss. Other studies have shown after bariatric surgery energy expenditure goes down initially but stabilizes after 1 or 2 years.

How about the hormones? Ghrelin is a hormone made by the stomach that signals the brain that you are hungry. In fact, it is the only hunger hormone known. Interestingly, people with obesity have lower ghrelin levels than lean people. It’s possible that people with obesity are more sensitive to ghrelin’s effect, however. Typically, ghrelin goes down quickly after eating but in people with obesity, there isn’t the same sharp drop leading to eating more or sooner after the meal. After weight loss, studies have shown ghrelin goes UP so people feel hungrier. Even if you don’t feel like you are starving, it will increase food intake though it may be subtle.

What about satiety hormones (those that cause fullness and satisfaction)? An important regulator of appetite is Leptin which is made in adipose (fat) cells. When you have less adipose after weight loss, there is less Leptin being made and therefore less of a signal to the brain that you are full and satiated. Other satiety hormones from the gastrointestinal tract also have been shown to be decreased after weight loss.

So how do we battle these hormonal and metabolic adaptations after weight loss? Higher levels of physical activity can counter the drop in resting energy expenditure with higher total energy expenditure. How much physical activity is enough? The National Weight Registry, an ongoing study started in 1993 has shown people who are successfully maintaining weight loss are doing about 300 or more minutes a week of planned physical activity (about 60 minutes 5x/week). Try for some aerobic activity (walking is good!) as well as some strength training. Having more muscle mass increases your resting energy expenditure.

What about your eating patterns and nutritional intake? Whatever dietary and behavioral changes you made to lose weight, continuing to adhere to them is really important for weight maintenance. Also, we can’t forget about getting adequate sleep (7-8 hours/night for adults)! Sleep deprivation has been shown in studies to increase ghrelin and decrease leptin therefore increasing food intake. Self-monitoring with weighing yourself regularly and food journalling also help.

If you were taking anti-obesity medication to help with weight loss, continuing to take it will also help with maintenance. If you thought of anti-obesity medication as a ‘jump start’, realize you’ll do better long-term changing your thinking. Anti-obesity medications are like blood pressure medication in when you take it, your blood pressure goes down and if you stop it, it goes back up. Same thing happens with your weight. Obesity is a chronic but relapsing disease and like hypertension or diabetes, continuous use of medication helps with control of the disease.

Continuing to get support from your obesity medicine or primary care providers, dietician, trainer, support group etc is also key. At Weigh to Wellness Denver we still want to see you regularly. Weight management is a lifelong endeavor for everyone, and we are happy to continue with you on your journey!