How Your Body Fights Weight Loss
Prepare for Your Weight Loss Journey
Updated December 2022
Weight management is a key part of a healthy life. While many people successfully maintain healthy weights through a balance of nutrition and activity, weight loss can be vital for the 73.6 % of adults in the U.S. who are overweight or who live with obesity. However, weight loss – particularly extreme weight loss – is more complicated than consuming fewer calories than you burn. As many as 90 percent of people who have lost a considerable amount of weight will gain it back.
The key element is you.— Matthew R. Pittman, MD
Sustainable weight management is possible and understanding how your body responds to weight loss efforts can help you establish realistic expectations on your journey.
Here are 8 things you may not know about your body and weight loss.
1. Your Metabolism Will Slow Down to Store Fat
The more you work out or manage your calorie intake to lose weight, the more your metabolism wants to compensate by slowing down to maintain your current weight, this is called metabolic compensation. It kicks in to preserve and store fat for future energy. Research shows that this happens because the human body has evolved to value storing fat and energy and to interpret a shortage of calories as sign of distress.
2. Your Hormones Will Increase Your Drive to Eat
Metabolic compensation isn’t the only way that your body’s can prevent weight loss or encourage weight gain. Fat cells produce leptin, which tells your brain when you’re full. Fat cells shrink when you lose weight, producing less leptin, which means that you don’t feel as full.
Your stomach produces ghrelin, which tells your brain when it’s time to refuel. When you lose weight, your ghrelin levels rise, making you want to eat more often.
3. Weight Loss Impacts Your Brain
When you lose weight, the part of your brain that regulates food restraint becomes less active – meaning that while you’re eating more to feel full (courtesy of leptin), you’re also less aware of how much you’re eating.
4. Your Genes Play a Role
More than 400 genes have been linked to obesity and weight gain, and they can affect appetite, metabolism, cravings and body-fat distribution. It is unclear how much you can be genetically predisposed to weight gain or obesity, but some genes have been associated with difficulty losing weight even as you increase physical activity or low-calorie diets.
If you have a genetic predisposition for obesity, it is easier to take a proactive stance to weight management. A preventive approach is more effective because you are preventing obesity from occurring in the first place.
5. Your Body Is Extra Prepared for Your Second Try
If you’ve lost weight in the past by exercising or changing your diet and try to use those strategies again to lose weight, your body ndash; mainly hormones and metabolism – will adjust to prevent similar damage and you’ll see fewer weight loss results.
6. Your Weight May Have a Favorite Number
Some scientists think that your body has a set point weight and your metabolism, hormones and brain will adjust to maintain that weight. People may have naturally higher or lower set weights than others; their set points can be impacted by genetics, aging, history of weight loss and hormonal shifts. The theory suggests that your set point weight can rise but rarely lower. It is easier to maintain your set point weight because your body wants to remain at that point – not lose weight.
7. Your Weight Loss Might Not Look Like You Expected
After successful weight loss, your body may look different than you were expecting. Stretch marks and loose skin are common, and many people deal with the emotional effects of coping with a body that doesn’t fit what they pictured
8. Your Emotional Health Is Independent of Your Weight
People often tie happiness and emotional health to weight loss. When they have successfully lost weight but remain dissatisfied with other parts of their life, they can fall into a cycle of dissatisfaction. Guilt at not feeling happy after weight loss can be a factor, as well as the temptation to eat to cope with these feelings. Some people can experience an uncertainty about their next goal is after losing significant amounts of weight.
What Can Help
Some simple strategies, such as making protein a staple of meals and snacks or starting a weight loss routine with cardio before switching to weight training and resistance later on, can help support your weight loss goals.
It’s helpful to focus on small, achievable lifestyle goals for your emotional health during your weight loss journey. For example, instead of looking for a low number on the scale, you may focus on reaching a point where you feel comfortable playing sports or attending a group fitness class.
Aiming for moderate goals that can build to bigger change can help you avoid the pitfalls of rapid, short-term solutions.
"Both medical and surgical-assisted weight loss programs have proven to be very successful, but the key element is you," says Matthew R. Pittman, MD director of Bariatric Surgery, Northwestern Medicine Regional Medical Group. " Committing fully to the behavioral and lifestyle changes required is essential for long-term weight loss success. "
Working with a lifestyle medicine professional can also help you manage expectations, set reasonable goals and respond to your body’s changes if weight loss is a goal of yours. You may also want to consider whether a nutritionist is right for you.
The team at the Northwestern Medicine Center for Lifestyle Medicine specializes in setting achievable goals ranging from comprehensive weight-loss treatment and management for adults to risk factor reduction and tools to improve physical activity and encourage healthy eating.