Many factors contribute to weight gain and obesity. These factors are both genetic, environmental and behavioral. It is important for a surgery candidate to understand what factors have lead to their obesity in order to succeed as a bariatric surgery patient.
As you get older you tend to lose muscle, especially if you’re less active. Muscle loss can slow down the rate at which your body burns calories. If you don’t reduce your calorie intake as you get older, you may gain weight.
Midlife weight gain in women is mainly due to aging and lifestyle, but menopause also plays a role. Many women gain around 5 pounds during menopause and have more fat around the waist than they did before beginning menopause.
Studies find that the less people sleep, the more likely they are to be overweight or obese. People who report sleeping 5 hours a night, for example, are much more likely to become obese compared with people who sleep 7–8 hours a night.
People who sleep fewer hours also seem to prefer eating foods that are higher in calories and carbohydrates, which can lead to overeating, weight gain, and obesity over time.
Hormones that are released during sleep control appetite and the body’s use of energy. For example, insulin controls the rise and fall of blood sugar levels during sleep. People who don’t get enough sleep have insulin and blood sugar levels that are similar to those in people who are likely to have diabetes. Getting minimal amounts of sleep also seems to cause people to have higher levels of a hormone called ghrelin (which causes hunger) and lower levels of a hormone called leptin (which normally helps curb hunger).
Some people eat more than usual when they’re bored, angry, or stressed. Over time, overeating will lead to weight gain and may cause obesity.
A common cause of obesity in a person is energy imbalance. To have balanced energy means that the energy you take IN equals the energy you put OUT.
Energy INPUT is the amount of energy (in calories) you ingest from food and drinks. Energy OUTPUT is the amount of energy (also in calories) your body uses for activities like breathing, digesting, and being physically active.
To maintain a healthy weight, your energy INPUT and OUTPUT don’t have to balance exactly every day. It’s the balance over time that helps you maintain a healthy weight.
- The same amount of energy INPUT and energy OUTPUT over time = weight stays the same
- More energy INPUT than energy OUTPUT over time = weight gain
- More energy OUTPUT than energy INPUT over time = weight loss
Obesity happens over time when you take in more calories than you use.
Our environment does not generally support healthy lifestyle habits; in fact, it encourages obesity. Some reasons include:
Lack of neighborhood sidewalks and safe places for recreation: Not having area parks, trails, sidewalks, and affordable gyms makes it hard for people to be physically active
Work schedules: People often say that they don’t have time to be physically active because of long work hours and time spent commuting.
Oversized food portions: Americans are surrounded by huge food portions in restaurants, fast food places, gas stations, movie theaters, supermarkets, and even home. Some of these meals and snacks can feed two or more people. Eating large portions means too much energy IN. Over time, this will cause weight gain if it isn’t balanced with physical activity.
Lack of access to healthy foods: Some people don’t live in neighborhoods that have supermarkets that sell healthy foods, such as fresh fruits and vegetables. Or, for some people, these healthy foods are too costly.
Americans are surrounded by ads from food companies. Often children are the targets of advertising for high-calorie, high-fat snacks and sugary drinks. The goal of these ads is to sway people to buy these high-calorie foods, and often they do.
Studies of identical twins who have been raised apart show that genes have a strong influence on a person’s weight. Obesity tends to run in families. Your chances of being overweight are greater if one or both of your parents are overweight or obese.
Your genes also may affect the amount of fat you store in your body and where on your body you carry the extra fat. Because families also share food and physical activity habits, a link exists between genes and the environment. Children adopt the habits of their parents. A child who has overweight parents who eat high-calorie foods and are inactive will likely become overweight too. However, if the family adopts healthy food and physical activity habits, the child’s chance of being obese is reduced.
Many Americans aren’t very physically active; they spend hours in front of TVs and computers doing work, schoolwork, or leisure activities. Activities such as these are linked directly to excess body fat. In fact, two hours or more of regular TV viewing has been shown to dramatically increase the likelihood of obesity in people. Leading a sedentary lifestyle in general increases your chances of becoming overweight or obese. Examples of this are:
- Relying on cars instead of walking
- Fewer physical demands at work or at home because of modern technology and conveniences
- Lack of physical education classes in schools for children
- People who are inactive are more likely to gain weight because they don’t burn up the calories that they take in from food and drinks. An inactive lifestyle also raises your risk of coronary heart disease, high blood pressure, diabetes, colon cancer, and other health problems.
Certain medicines may cause you to gain weight. These medicines include some corticosteroids, antidepressants, and seizure medicines.
These medicines can slow the rate at which your body burns calories, increase your appetite, or cause your body to hold onto extra water. All of these factors can lead to weight gain.