Obesity

From Mayo Clinic

Overview

Obesity is a complex disorder involving an excessive amount of body fat. Obesity isn't just a cosmetic concern. It increases your risk of diseases and health problems, such as heart disease, diabetes and high blood pressure.

Being extremely obese means you are especially likely to have health problems related to your weight.

The good news is that even modest weight loss can improve or prevent the health problems associated with obesity. Dietary changes, increased physical activity and behavior changes can help you lose weight. Prescription medications and weight-loss surgery are additional options for treating obesity.

Symptoms

Obesity is diagnosed when your body mass index (BMI) is 30 or higher. Your body mass index is calculated by dividing your weight in kilograms (kg) by your height in meters (m) squared.

BMI Weight status
Below 18.5 Underweight
18.5-24.9 Normal
25.0-29.9 Overweight
30.0-34.9 Obese (Class I)
35.0-39.9 Obese (Class II)
40.0 and higher Extreme obesity (Class III)

For most people, BMI provides a reasonable estimate of body fat. However, BMI doesn't directly measure body fat, so some people, such as muscular athletes, may have a BMI in the obese category even though they don't have excess body fat. Ask your doctor if your BMI is a problem.

When to see a doctor

If you think you may be obese, and especially if you're concerned about weight-related health problems, see your doctor or health care provider. You and your provider can evaluate your health risks and discuss your weight-loss options.

Causes

Although there are genetic, behavioral and hormonal influences on body weight, obesity occurs when you take in more calories than you burn through exercise and normal daily activities. Your body stores these excess calories as fat.

Obesity can sometimes be traced to a medical cause, such as Prader-Willi syndrome, Cushing's syndrome, and other diseases and conditions. However, these disorders are rare and, in general, the principal causes of obesity are:

  • Inactivity. If you're not very active, you don't burn as many calories. With a sedentary lifestyle, you can easily take in more calories every day than you use through exercise and normal daily activities.
  • Unhealthy diet and eating habits. Weight gain is inevitable if you regularly eat more calories than you burn. And most Americans' diets are too high in calories and are full of fast food and high-calorie beverages.

Risk factors

Obesity usually results from a combination of causes and contributing factors, including:

  • Genetics. Your genes may affect the amount of body fat you store, and where that fat is distributed. Genetics may also play a role in how efficiently your body converts food into energy and how your body burns calories during exercise.
  • Family lifestyle. Obesity tends to run in families. If one or both of your parents are obese, your risk of being obese is increased. That's not just because of genetics. Family members tend to share similar eating and activity habits.
  • Inactivity. If you're not very active, you don't burn as many calories. With a sedentary lifestyle, you can easily take in more calories every day than you burn through exercise and routine daily activities. Having medical problems, such as arthritis, can lead to decreased activity, which contributes to weight gain.
  • Unhealthy diet. A diet that's high in calories, lacking in fruits and vegetables, full of fast food, and laden with high-calorie beverages and oversized portions contributes to weight gain.
  • Medical problems. In some people, obesity can be traced to a medical cause, such as Prader-Willi syndrome, Cushing's syndrome and other conditions. Medical problems, such as arthritis, also can lead to decreased activity, which may result in weight gain.
  • Certain medications. Some medications can lead to weight gain if you don't compensate through diet or activity. These medications include some antidepressants, anti-seizure medications, diabetes medications, antipsychotic medications, steroids and beta blockers.
  • Social and economic issues. Research has linked social and economic factors to obesity. Avoiding obesity is difficult if you don't have safe areas to exercise. Similarly, you may not have been taught healthy ways of cooking, or you may not have money to buy healthier foods. In addition, the people you spend time with may influence your weight — you're more likely to become obese if you have obese friends or relatives.
  • Age. Obesity can occur at any age, even in young children. But as you age, hormonal changes and a less active lifestyle increase your risk of obesity. In addition, the amount of muscle in your body tends to decrease with age. This lower muscle mass leads to a decrease in metabolism. These changes also reduce calorie needs, and can make it harder to keep off excess weight. If you don't consciously control what you eat and become more physically active as you age, you'll likely gain weight.
  • Pregnancy. During pregnancy, a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women.
  • Quitting smoking. Quitting smoking is often associated with weight gain. And for some, it can lead to enough weight gain that the person becomes obese. In the long run, however, quitting smoking is still a greater benefit to your health than continuing to smoke.
  • Lack of sleep. Not getting enough sleep or getting too much sleep can cause changes in hormones that increase your appetite. You may also crave foods high in calories and carbohydrates, which can contribute to weight gain.

Even if you have one or more of these risk factors, it doesn't mean that you're destined to become obese. You can counteract most risk factors through diet, physical activity and exercise, and behavior changes.

Complications

If you're obese, you're more likely to develop a number of potentially serious health problems, including:

  • High triglycerides and low high-density lipoprotein (HDL) cholesterol
  • Type 2 diabetes
  • High blood pressure
  • Metabolic syndrome — a combination of high blood sugar, high blood pressure, high triglycerides and low HDL cholesterol
  • Heart disease
  • Stroke
  • Cancer, including cancer of the uterus, cervix, endometrium, ovaries, breast, colon, rectum, esophagus, liver, gallbladder, pancreas, kidney and prostate
  • Breathing disorders, including sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts
  • Gallbladder disease
  • Gynecological problems, such as infertility and irregular periods
  • Erectile dysfunction and sexual health issues
  • Nonalcoholic fatty liver disease, a condition in which fat builds up in the liver and can cause inflammation or scarring
  • Osteoarthritis

Quality of life

When you're obese, your overall quality of life may be diminished. You may not be able to do things you used to do, such as participating in enjoyable activities. You may avoid public places. Obese people may even encounter discrimination.

Other weight-related issues that may affect your quality of life include:

  • Depression
  • Disability
  • Sexual problems
  • Shame and guilt
  • Social isolation
  • Lower work achievement

Prevention

Whether you're at risk of becoming obese, currently overweight or at a healthy weight, you can take steps to prevent unhealthy weight gain and related health problems. Not surprisingly, the steps to prevent weight gain are the same as the steps to lose weight: daily exercise, a healthy diet, and a long-term commitment to watch what you eat and drink.

  • Exercise regularly. You need to get 150 to 300 minutes of moderate-intensity activity a week to prevent weight gain. Moderately intense physical activities include fast walking and swimming.
  • Follow a healthy eating plan. Focus on low-calorie, nutrient-dense foods, such as fruits, vegetables and whole grains. Avoid saturated fat and limit sweets and alcohol. Eat three regular meals a day with limited snacking. You can still enjoy small amounts of high-fat, high-calorie foods as an infrequent treat. Just be sure to choose foods that promote a healthy weight and good health most of the time.
  • Know and avoid the food traps that cause you to eat. Identify situations that trigger out-of-control eating. Try keeping a journal and write down what you eat, how much you eat, when you eat, how you're feeling and how hungry you are. After a while, you should see patterns emerge. You can plan ahead and develop strategies for handling these types of situations and stay in control of your eating behaviors.
  • Monitor your weight regularly. People who weigh themselves at least once a week are more successful in keeping off excess pounds. Monitoring your weight can tell you whether your efforts are working and can help you detect small weight gains before they become big problems.
  • Be consistent. Sticking to your healthy-weight plan during the week, on the weekends, and amidst vacation and holidays as much as possible increases your chances of long-term success.

*source: https://www.mayoclinic.org/diseases-conditions/obesity/symptoms-causes/syc-20375742

 

From blogs.scientificamerican.com

The Biggest Health Problem: Obesity

Credit: Getty Images

As the chief of epidemiology at a major medical school, I am frequently asked what the biggest threat is to the health of our nation. My response is obesity.

The obesity epidemic is a public health crisis in the U.S. Over one -third of all adults are obese; and another two thirds are overweight and on the way to becoming obese. In racial and ethnic minority groups including blacks, Hispanics and Native Americans, obesity has touched nearly half of the adult population.

That is why I cheered when I read the findings of a recent study describing how effective a beverage tax was on lowering the consumption of sugar-sweetened beverages in Philadelphia. 

The logical first line of defense against obesity is individual behavior changes to promote healthy lifestyles. However, individual behavior change is ineffective in the face of social and structural barriers that constrain individual choice. These barriers are uniquely relevant among racial and ethnic minorities and impoverished adults who are more likely to be obese.

Across a lifetime, obesity contributes to the development of physical illnesses including cardiovascular diseases and lung disease, mental illnesses such as depression, and disabilities including osteoarthritis.

Obesity is also responsible for perpetuating disparities in multiple chronic diseases by race, ethnicity and socioeconomic class.  For example, the disparate burden of obesity in blacks may explain elevated rates of heart failure and stroke in black men and women as compared with whites.

One reason why I support using sin taxes such as the sugared beverage tax to regulate unhealthy behaviors that contribute to obesity is because their reach is broader than individual interventions.

The “prevention paradox” as described by British epidemiologist Geoffrey Rose in a 1985 study that was republished in 2001, states that “large numbers of people must participate in a prevention strategy for direct benefit to relatively few.”

I had a firsthand look at the origins of socioeconomic disparities in childhood obesity when we enrolled our child in a home-based daycare because it was much less costly than its commercial counterpart. Our daycare provider received subsidies from the state because she was serving a large population of low-income children. She used those subsidies to purchase food and beverages for the children.

During snack time, she served chips and juice to the children. Alarm bells went off for our family. The absence of policies restricting the use of state funds to feed children was a missed opportunity to avert bad lifestyle habits. Had there been a tax in place on sugared beverages, I wonder whether her purchasing patterns, and the children’s consumption patterns, would have changed.

 

*source: https://blogs.scientificamerican.com/observations/the-biggest-health-problem-obesity/

 

from: World Health Organization websites

Overweight and Obesity Definitions

obesity symbol

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. A crude population measure of obesity is the body mass index (BMI), a person’s weight (in kilograms) divided by the square of his or her height (in metres). A person with a BMI of 30 or more is generally considered obese. A person with a BMI equal to or more than 25 is considered overweight.

Overweight and obesity are major risk factors for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer. Once considered a problem only in high income countries, overweight and obesity are now dramatically on the rise in low- and middle-income countries, particularly in urban settings.

 

*source: https://www.who.int/topics/obesity/en/

 

Diet

Unhealthy diets and physical inactivity are major risk factors for chronic diseases. Reports of international and national experts and reviews of the current scientific evidence recommend goals for nutrient intake in order to prevent chronic diseases.

For diet, recommendations for populations and individuals should include the following:

  • achieve energy balance and a healthy weight
  • limit energy intake from total fats and shift fat consumption away from saturated fats to unsaturated fats and towards the elimination of trans-fatty acids
  • increase consumption of fruits and vegetables, and legumes, whole grains and nuts
  • limit the intake of free sugars
  • limit salt (sodium) consumption from all sources and ensure that salt is iodized

These recommendations need to be considered when preparing national policies and dietary guidelines, taking into account the local situation.

Improving dietary habits is a societal, not just an individual problem. Therefore it demands a population-based, multisectoral, multi-disciplinary, and culturally relevant approach.

 

*source: https://www.who.int/dietphysicalactivity/diet/en/

 

From stanfordhealthcare.org

Treating Obesity through Diet

Fad diets come and go. Some, like low carb and high protein and fat diets, may work in the short term, but they can also pose serious health risks in the long run. Ultimately, the most successful long-term weight loss programs rely more on limiting how many calories you consume, and how many you burn through exercise and daily activity, rather than the actual composition of the diet.

Fasting may result in rapid weight loss, but you lose important lean muscle mass along with fat. All-liquid diets, which must be medically supervised, may be used for a short period of time, but these diets don't offer a long-term answer to weight loss.

Fads diets, which haven't had their health effects determined by rigorous clinical trials, may not be healthy options for weight loss. However, if you follow certain basic dietary recommendations, they can lead to weight loss:

  • To lose weight and keep it off, instead of thinking "diet," think about an individualized eating plan. A plan that's tailored to your personal likes and dislikes will have a better chance of producing lasting weight loss. A balanced diet that restricts calorie intake—1,200 to 1,400 calories for women and 1,500 to 1,800 calories for men—may work well. A registered dietician can help to make an individualized diet plan based on your particular situation.
  • Include a variety of foods in the diet.
  • All fats are not bad. We now know that polyunsaturated and monosaturated fats provide health benefits such as helping to keep the heart healthy. This means that nuts, seeds, and some types of oils, such as olive, safflower and canola, can be part of a healthy eating plan.
  • Choose whole grains such as brown rice and whole wheat bread rather than white rice and white bread. Whole grain foods are richer in nutrients and higher in fiber, so the body absorbs them more slowly. This means they won't cause a rapid spike in insulin, which can trigger hunger and cravings.
  • Get at least five servings daily of a variety of fruits and vegetables. Different fruits and vegetables contain varying amounts and types of nutrients.
  • When dining out, ask for a take-home box, and avoid super-sized selections when you order take-out food. Many restaurant portions are too large for one person, so consider sharing an entrée or ordering an appetizer instead of a main dish from the entrée menu.
  • Read food labels carefully. Pay particular attention to the number of servings contained in the product and the serving size. If the label says a serving is 150 calories and there are three servings per container, if you eat the entire contents of the container, you've consumed 450 calories. 

 

https://stanfordhealthcare.org/medical-conditions/healthy-living/obesity/treatments/diet.html

 

How to Prevent Obesity

Obesity is a chronic disease affecting more and more children, adolescents and adults:

  • Obesity rates among children in the U.S. have doubled since 1980 and have tripled for adolescents
  • 15% percent of children aged six to 19 are considered overweight
  • Over 60 percent of adults are considered overweight or obese

Healthcare professionals are seeing earlier onset of Type 2 diabetes (normally an adult-onset disease), cardiovascular disease and obesity-related depression in children and adolescents. The longer a person is obese, the more significant obesity-related risk factors become. Given the chronic diseases and conditions associated with obesity, and the fact that obesity is difficult to treat, prevention is extremely important.

A primary reason that prevention of obesity is so vital in children is because the likelihood of obese becoming obese adults is thought to increase from about 20 percent at four years of age to 80 percent by adolescence.

Preventing Obesity in Infants

The longer babies are breastfed, the less likely they are to become overweight as they grow older. Breastfed babies are 15 to 25 percent less likely to become overweight. For those who are breastfed for six months or longer, the likelihood is 20 to 40 percent less. 

Preventing Obesity in Children and Adolescents

Young people generally become overweight or obese because they don't get enough physical activity in combination with poor eating habits. Genetics and lifestyle also contribute to a child's weight status.

There are a number of steps you can take to help prevent overweight and obesity during childhood and adolescence. (They'll help you, too!) They include:

  • Gradually work to change family eating habits and activity levels rather than focusing on weight. Change the habits and the weight will take care of itself.
  • Be a role model. Parents who eat healthy foods and are physically activity set an example that increases the likelihood their children will do the same.
  • Encourage physical activity. Children should have an hour of moderate physical activity most days of the week. More than an hour of activity may promote weight loss and subsequent maintenance.
  • Reduce time in front of the TV and computer to less than two hours a day.
  • Encourage children to eat only when hungry, and to eat slowly.
  • Avoid using food as a reward or withholding food as a punishment.
  • Keep the refrigerator stocked with fat-free or low-fat milk and fresh fruit and vegetables instead of soft drinks and snacks high in sugar and fat.
  • Serve at least five servings of fruits and vegetables daily.
  • Encourage children to drink water rather than beverages with added sugar, such as soft drinks, sports drinks and fruit juice drinks. 

Preventing Obesity in Adults

Many of the strategies that produce successful weight loss and maintenance will help prevent obesity. Improving your eating habits and increasing physical activity play a vital role in preventing obesity. Things you can do include:

  • Eat five to six servings of fruits and vegetables daily. A vegetable serving is one cup of raw vegetables or one-half cup of cooked vegetables or vegetable juice. A fruit serving is one piece of small to medium fresh fruit, one-half cup of canned or fresh fruit or fruit juice, or one-fourth cup of dried fruit.
  • Choose whole grain foods such as brown rice and whole wheat bread. Avoid highly processed foods made with refined white sugar, flour and saturated fat.
  • Weigh and measure food to gain an understanding of portion sizes. For example, a three-ounce serving of meat is the size of a deck of cards. Avoid super-sized menu items particularly at fast-food restaurants. You can achieve a lot just with proper choices in serving sizes.
  • Balance the food "checkbook." Eating more calories than you burn for energy will lead to weight gain.
  • Weigh yourself regularly.
  • Avoid foods that are high in "energy density" or that have a lot of calories in a small amount of food. For example, a large cheeseburger and a large order of fries may have almost 1,000 calories and 30 or more grams of fat. By ordering a grilled chicken sandwich or a plain hamburger and a small salad with low-fat dressing, you can avoid hundreds of calories and eliminate much of the fat intake. For dessert, have fruit or a piece of angel food cake rather than the "death by chocolate" special or three pieces of home-made pie.
  • Crack a sweat: accumulate at least 30 minutes or more of moderate-intensity activity on most, or preferably, all days of the week. Examples include walking a 15-minute mile, or weeding and hoeing the garden.
  • Make opportunities during the day for even just 10 or 15 minutes of some calorie-burning activity, such as walking around the block or up and down a few flights of stairs at work. Again, every little bit helps. 

 

*source: https://stanfordhealthcare.org/medical-conditions/healthy-living/obesity/prevention.html