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Weight Gain is Much More Complex than ‘Calories in, Calories Out’

Many people who struggle with their weight believe they are to blame. What most people fail to realize, however, is that while overeating, poor nutrition and a sedentary lifestyle certainly do contribute to weight gain, there are also many genetic, metabolic and psychological factors that can make it difficult to achieve meaningful weight loss.

“I have a deep well of empathy for my patients, because, in many cases, they are working against aspects of their biology that aren’t entirely within their control,” says Ashley Haralson Vernon, MD, a bariatric surgeon in the Division of General and Gastrointestinal Surgery at Brigham Health.

A wide body of research, for example, has shown that each person has a biological set point that regulates their weight within a fairly narrow range. For some people, that range may skew lower or higher than a healthy weight. For those with a higher set point, it can be challenging to maintain a normal weight.

Many individuals also struggle with their weight because of a combination of genetic influences. Studies have identified variants in several genes that contribute to weight gain by altering the hormones that control feelings of satiety or fullness. When these hormones function incorrectly, feelings of hunger can increase and cause a person to overeat. Additionally, some genes affect metabolism and increase the tendency to store body fat.

Likewise, some medical conditions or medications can result in excess weight gain. An underactive thyroid (hypothyroidism), polycystic ovary syndrome (PCOS), and Cushing’s Syndrome can all contribute to weight gain. Meanwhile, certain medications to treat diabetes, epilepsy, depression and high blood pressure can impact one’s weight, as can antipsychotics, corticosteroids, and birth control pills.

Maintaining a healthy weight can also be challenging for those who are consistently experiencing negative emotions, such as stress or anxiety. Studies have shown that while short-term stress can temporarily shut-down hunger, long-term stress can trigger an increase in cortisol levels that contribute to weight gain.

“Regardless of the causes, it has become abundantly clear that weight gain can’t be chalked up to a simple lack of willpower or poor lifestyle habits,” says Dr. Vernon.

Every one of Dr. Vernon’s patients has been struggling with their weight long before they enter her office. Some have been progressively gaining weight over the last 20 to 30 years even though they have been trying to lose weight their entire lives.

All of these individuals have tried diets and exercise programs without success. The majority are women (~80 percent), middle-aged, and about one hundred pounds overweight. Many also have high blood pressure, diabetes, and/or sleep problems.

At some point, many patients start to feel like the cards are stacked against them. A woman in her seventies recently visited Dr. Vernon when she finally admitted to herself that she just couldn’t lose the weight on her own. She had been gaining weight since her forties. Her knees constantly ached, and she hadn’t slept through the night in years.

At Brigham Health, weight loss procedures are offered at the Center for Metabolic and Bariatric Surgery. About two-thirds of the patients who visit are eligible for the three most common weight-loss procedures. These include: gastric bypass, sleeve gastrectomy, and adjustable gastric banding.

These weight loss procedures involve minimally invasive surgical manipulation of the stomach, and sometimes the small intestine, to reduce food intake. To qualify, a patient must have a BMI of 40 or higher, or a BMI of 35-40 and a related health condition, such as high blood pressure, diabetes or sleep apnea.

Weight loss surgery isn’t a quick fix, however. It’s a jumpstart to a healthier lifestyle and requires a lifelong commitment to health and wellness. That’s why weight loss surgeries are performed alongside a commitment to eating well and exercising. To help make this transition easier, the Brigham offers patients a lifetime of support and guidance to ensure that the weight lost through surgery stays off for years to come.

“Weight loss surgery causes rapid weight reduction and gives patients a fresh start. Patients have the opportunity to reset many behaviors from scratch. We offer all the support a patient needs to do just that,” says Dr. Vernon.