Contrary to popular belief, obesity is rarely caused only by our genes. According to the Harvard School of Public Health (HSPH), the genetic factors linked to obesity comprise only a small part of the overall risk. However, the CDC notes that the variation in how people’s weight responds to the same environment suggests that genes do play a role in the development of obesity. Sometimes even people who carry genes associated with obesity don't become overweight, and vice versa. That's because, along with possible genetic factors, weight is also influenced by lifestyle factors. Even with a genetic predisposition, those who are overweight or obese may be able to change their weight slowly, through altering lifestyle habits and with support from family and friends. If your weight remains unchanged, healthy lifestyle habits will still make you healthier, regardless of what the scale weighs in at.

HPSH reports that researchers have identified certain rare instances in which obesity seems to be caused solely by genetic mutations. One such rare form of obesity, called "monogenetic obesity," appears to be caused by spontaneous mutations in single genes that are involved in appetite control and food intake. Certain genetic syndromes are also linked to obesity, including Prader-Willi and Bardet-Biedl syndromes.

Another condition known as "common obesity" may also have a genetic link, based on evidence from animal models and twin studies. According to HPSH, this form of obesity is believed to be affected by multiple genes rather than a single gene. Common obesity may help explain why some people tend to carry more body fat than others. But it's not the whole story — lifestyle factors are also important.

Fortunately, HPSC assures us that when it comes to obesity, your heredity rarely determines your weight destiny. While some people may be genetically predisposed to obesity, making healthy changes in your diet, lifestyle, and environment can counteract a genetic predisposition.

There are several small lifestyle changes that may help to prevent obesity, in yourself and in your family. Reduce your risk of obesity by taking these three steps:

1. Walk regularly

You may help keep your weight under control simply by walking 30 minutes a day, five days a week. According to the American Heart Association (AHA), a 150-pound person burns 240 calories per hour by walking. Worried about the time commitment? Relax. You can break the 30 minutes into shorter sessions. Try walking for 10 minutes in the morning before work, and 10 minutes during your lunch break. Then, try finishing your day with a 10-minute stroll after dinner. The more you move, the better off you are, both in terms of calorie burn and overall health.

2. Follow the dietary guidelines

The U.S. Department of Agriculture has a website called that offers guidance and education on healthy eating, nutrition, and diet. Keep it simple by sticking to the advice on the site if you feel uncertain about how to control your weight through diet. You may need to work toward increasing your intake of healthier foods. The MyPlate food guide recommends that you fill at least half your plate with fruits and veggies at each meal. There is also the option to track what you eat on the site so that you can identify habits that you can improve.

3. Learn to manage stress and get quality sleep

Many studies suggest a link between stress and obesity. A review of 14 studies published in theJournal of the Academy of Nutrition and Dieteticsfound a strong link between increased stress and unhealthy eating habits, along with higher body weight. Handling stress isn't always easy, but you can take small steps to feel more relaxed, such as by spending time with family and friends or trying yoga or meditation.

Moreover, you might be amazed at how much better you feel when you get a proper night's sleep. Many recent studies have identified a link between lack of sleep and hormonal changes that can lead to weight gain.

The good news is that obesity is not solely due to genetics. It's a condition that can usually be managed with lifestyle changes. Even when a genetic predisposition to obesity exists, HSPH notes that leading a healthy lifestyle may be the best way to counteract gene-related risks. Without weight loss, healthy lifestyle habits can increase your quality and quantity of life. If you are overweight or obese, or if you are at a high risk for obesity, it may be time to make some small changes in your eating and exercise habits.

Change can be intimidating, especially if you've tried to lose weight in the past. Instead of aiming for a total lifestyle overhaul, try focusing on a few small modifications that you can make in your day-to-day life. Not sure where to start? Try walking, cutting back on sweet beverages like juice, and making an effort to get a better night's sleep. You may find that small changes like these make a big difference when it comes to managing your weight.