There are many mechanisms as to why those who lose weight regain it so easily and it mainly has to do with an imbalance of certain hormones and food addiction.
The role of hormones in weight regain:
When people lose a significant amount of weight there is a decrease in the gut hormones that suppress appetite (GLP-1, Leptin, Amylin, etc.) and an increase in the hormones that stimulate hunger (mainly Ghrelin and AgRP) --thus all hormones point in the favor of increased food intake which leads to weight gain. The changes in our gut hormones make it very difficult for these individuals to know when they are hungry and if they are truly full -- this leads to overeating until the point of discomfort at times.
Many obese patients tell me that they are "addicted" to food. Their behavior is the same as those with addictions to alcohol or drugs:
I look at obesity as an addiction to food -- and in my opinion its one of the hardest addictions to quit. Food is a huge part of our culture and is always around us. Those who are obese have to be very strong willed and adamant to say "no". I remember one patient telling me that even "moderation" is difficult after weight loss -- its either you eat none of the "bad" foods or "you lose control and binge". Its an "all or nothing response." This is typical of other addictions as well and its the reason why its so easy to "relapse" back into weight gain.
Is there any way to prevent weight regain?
Yes, I do believe there are ways to prevent weight regain. It all starts with a focus on behavioral change. I educate my patients to understand whats going on with their bodies after they lose weight and why its so difficult to maintain weight loss.
I explain to them that they are in a constant battle with their mind and body due to the hormonal changes associated with weight loss. Their body has maintained a certain size for many years, and their body wants to do everything to go back to that weight its used to. They need to constantly say no to cravings and understand the difference between true hunger and habitual eating.
For example - I work with patients to establish their daily caloric needs to maintain their normal bodily functions. I then teach them how to calorie count and estimate the calories that are in the foods that they consume. Often times, patients will tell me that they are "starving"through the day with just 3-4 meals --even though they are consuming the exact calories that their body needs. I help patients identify that their body and mind "trick" them into thinking they are starving, even when they aren't because it wants them to gain weight. The trick is to outsmart one's own body and mind and just say "no." Sometimes I tell my patients to even just drink 2 cups of water to trick their brain into thinking its full or satisfied.
Addiction is another component of obesity for many individuals. Thus one way to prevent weight regain is to treat obesity like any other addiction. This is important for patients who use food as an emotional crutch. Most of my patients who are obese can identify a traumatic event that led to weight gain (physical/sexual abuse, loss of a family member, etc.). The first step is to identify the emotional/psychological issues that the patient might be dealing with and help overcome those first - this can be done with help of a psychiatrist.
The next important step to preventing weight regain is avoiding bad foods.
Think of obesity like an addiction -- do recovering alcoholics ever start drinking "every now and then"? They most definitely don't even think of having a single drink because of their potential to relapse. The same thing can happen with food, and is the reason that obese people tend to binge eat.
How can the healthcare community do a better job to help people deal with weight loss?
I believe that the key to preventing weight regain is through the healthcare community identifying obesity and weight loss management as a chronic disease. Currently there are too many barriers in place to provide these patients with the care that they need - weight loss medications are expensive, insurance does not cover for the appropriate number of visits to a doctor, nutritionist or therapist. These resources are so important, and part of the reason why these patients are struggling with weight regain.
People assume that once an obese person loses weight, their issues are resolved. This is far from the truth. Though weight loss will help them prevent many diseases (diabetes, high blood pressure, sleep apnea, etc.) -- they still have to struggle with acceptance of a new body and image (which is actually much harder than you would expect), constant cravings, food addictions, binge eating, bad habits, learning how to balance their lives and a healthy lifestyle. The healthcare community needs to identify weight loss management as a lifelong issue that should be addressed with the patient at each encounter to ensure they are not gaining weight and that they are happy with their lives.
We need to empathize with obese patients who struggle with life every single day. The more people who are out there to support these patients emotionally and physically, the less likely they are to regain weight.
