Obesity
What is obesity?
Body weight is based on the amount of calories consumed through food and the amount of calories used (burned) by activities of daily living. If you eat more calories than you use, you will gain weight. If you burn more calories than you consume, you will lose weight.
This is somewhat oversimplified, however. Factors that drive how much a person eats or how many calories he or she burns are complicated and can influence weight. Genetics, childhood experiences, and social and cultural influences all impact eating, individual metabolism, and physical activity. Even the physical environment influences your choices. For example, living next to a park with walking trails might help you become more physically active.
Obesity, or being overweight is not just a cosmetic issue. It is dangerous and can lead to numerous health problems and early death. Overweight and obesity are extremely common in industrialized countries like the U.S. and has been on the rise over the last few decades. For this reason, government and health associations have been making efforts to educate people about weight, good nutrition and the importance of losing excess weight.
Key points:
1. Obesity, or being overweight, is a dangerous condition that can lead to serious health problems
2. Weight is determined by how many calories a person consumes and how much they use up; when more calories are eaten than burned, people will gain weight
3. What drives a person to eat too much or burn too few calories is complicated and involves many factors, including genes, habits, childhood experiences, social and cultural influences, and individual metabolism.
What are the symptoms?
Obesity itself doesn’t cause symptoms, but it can cause or worsen diseases which have symptoms of their own, including:
- Arthritis – symptoms include pain in the back, knees, and hips caused by extra stress on the joints from excess body weight
- Hypertension (high blood pressure) – often causes no symptoms, when severe may include chest pain, shortness of breath, and headache
- Diabetes (high blood sugar) – left untreated, it can cause blurry vision, frequent urination, infections, sores that won’t heal, and fatigue
- Obstructive sleep apnea – Periods of stopped breathing (apnea) during sleep; symptoms include fatigue and snoring
Key Points
1. Obesity does not cause symptoms of its own but causes or worsens many diseases and their symptoms
2. Among the many diseases caused or worsened by obesity: Arthritis, hypertension, diabetes, and obstructive sleep apnea.
What are the risk factors?
The obvious risk factors for obesity are eating too many high calorie foods, and exercising too little, or a combination of both. As discussed earlier, various forces are acting to influence these behaviors. The following lifestyle factors may add to the likelihood risk of gaining excess weight:
1. Lack of time to prepare healthy meals
2. Lack of education about healthy versus unhealthy foods
3. Lack of access to healthy foods
4. Lack of time or no desire to exercise regularly
5. Being sedentary at home or at work
In addition, certain life circumstances seem to be very conducive to gaining weight. The college years a common period of weight gain. And many women find it very difficult to lose the weight they gained during pregnancy.
Some medical conditions, such as hypothyroidism and Cushing’s disease, can actually cause people to gain weight. Most often, the causes are not medical, but are lifestyle-related.
Key Points
1. The main risk for obesity is eating too many calorie-rich foods and not getting enough exercise
2. Many lifestyle issues add to the risk, including lack of time to prepare healthy meals, lack of time or desire to exercise, and being sedentary at work or home
3. Medical conditions can cause obesity, but most cases are due to lifestyle issues
How is it diagnosed?
Another way to determine whether or not you are overweight or obese is to compare the ration of waist circumference to hip circumference. A higher ratio indicates that more fat is carried in the abdominal area in relation to the hips and buttocks. The higher the ratio, the greater the risk of heart disease. Determining waist-to-hip ratio requires careful and precise measurements, and is best done in a healthcare provider’s office.
Key points
1. BMI is the most convenient way to determine if you are overweight or obese. To determine your BMI, visit: http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/risk.htm.
2. Waist-to-hip ratio is another good way to determine if you are overweight and at higher risk of heart disease; this should be done in a healthcare provider’s office
How is it treated?
The key to weight loss is reducing caloric intake (diet) and increasing caloric output (physical activity. The goal of diet and exercise is to create a calorie deficit, meaning that more calories are burned than consumed. This can be done by dieting without exercise, or exercising without dieting, but a [A] combination of both diet and exercise is more likely to be successful and is better for general health.
A general guideline is that, if you have a calorie deficit of 500 calories per day, you will lose an average of 1 pound per week. This does not mean you should eat only 500 calories a day. Rather, the number of calories you eat each day should be 500 calories less than the number of calories you burn. For example, if you reduce your caloric intake by 200 calories and also burn an extra 300 calories, this equals a caloric deficit of 500 calories.
Remember, it may take time for your body time to adjust to a weight loss program. The pounds may not come off easily at first, but they will eventually. Losing about one pound per week is a reasonable goal. Slow, steady weight loss is more likely to succeed.
Recommended diets:
Despite extensive research, there is no “perfect” diet for everyone. High protein, low carbohydrate diets may work for some, others may respond better to lowering fats and sugars. What’s most important is that a diet be healthy and reasonable enough for someone to stick with over the long term. Radical diets or supplements that promise rapid weight loss may sound tempting, but may not be safe or effective in the long run. The best way to find a diet will work for you is to visit your doctor and/or see a nutritionist. There are many well-recognized organizations (e.g., Weight Watchers. Overeaters Anonymous) that can help provide good advice and support. The U.S. Department of Health sponsors a website that provides numerous sources for good dietary advice. It is available at: http://win.niddk.nih.gov/. [You may also consider joining an established organization (e.g., Weight Watchers), or seeking information from reputable web sites, such as http://win.niddk.nih.gov/. ]
Physical activity
Your body burns calories just to keep you alive. But extra physical activity is an important part of losing weight. It can also help keep off the pounds that you already lost. Walking is a perfectly good exercise and requires no special equipment. Try to gradually build up to walking for 30-60 minutes on most days of the week. Gentle exercise (e.g. walking) for longer periods (e.g. 60 minutes) is better for most people since the chance for injury is lower than with running. Joining a gym, taking up a physically active sport or hobby (e.g., tennis, hiking), using exercise tapes in the home are just a few ways to increase daily activity. Even simple measures, such as walking instead of taking a bus or cab, using stairs instead of elevators or escalators, and parking further away from your destination can make a difference.
[Ways to increase physical activity:
– Walking 30 to 60 minutes a day
– Joining a gym
– Engaging in active sports or activities
– Using exercise tapes]
– Walking instead of riding a bus or taking a taxi, using stairs instead of elevators, parking further away from destinations]
The importance of physical activity cannot be overemphasized. Besides losing weight, physical activity has other benefits, such reducing the risk of diabetes, high blood pressure, heart disease, and some cancers.
Drugs
Weight loss medications are a “short-term solution to a long-term problem” and should only be used when diet and exercise has failed. Available prescription medications can cause significant side effects and should be used for short periods of time as prescribed by a doctor. They include: Phentermine, benzphetamine, phendimetrazine. Sibutramine (Meridia“) is an appetite suppressant approved for use up to 1 year. Side effects include elevated blood pressure and heart rate. [and] Orlistat (Xenical“) reduces the amount of dietary fats absorbed by the gastrointestinal tract. Side effects include diarrhea and oily stool.
Weight loss drugs should be taken under close supervision of a qualified physician. Since most prescription agents result in only moderate weight loss, it is important to continue diet and exercise even while talking a weight loss medication. It is not recommended to take more than one weight loss drug at a time.
NOTE: There are many over-the-counter products that claim to boost metabolism and promote weight loss. Most are unproven and some may contain dangerous ingredients. There is also no way to know if the products contain the promoted ingredients or how pure they are. Please consult with a physician or professional healthcare provider before taking any of these products.
Surgery
Surgery is considered a “last resort” option for weight loss. Gastric bypass and gastric banding are the most common weight loss operations today. They work by shrinking space in the stomach, which reduces caloric intake. Although weight loss surgery can produce long-term weight loss, it is not for everybody. The operations are becoming safer, but serious complications can still occur. Surgery should be reserved for those with extreme obesity (BMI more than 40 kg/m2) or those with severe complications of obesity, such as diabetes, high blood pressure, heart disease, or sleep apnea. Individuals should try diet and exercise before undergoing surgery, and they should continue diet and exercise after surgery.
Key Points
1. Weight loss requires a caloric deficit – i.e., less calories consumed then are burned per day
2. To lose one pound, you need to burn 500 more calories than you eat daily, preferably by combining diet and exercise; aiming to lose about one pound per week is a realistic, healthy goal.
3. To determine the best diet for you, seek guidance from a doctor, nutritionist, or reputable weight loss organization; it’s best to avoid extreme, rapid-weight loss diets
4. Weight loss medications and surgery are appropriate a select group of people who are severely overweight and have not been able to lose weight with diet and exercise.
5. Consult with a healthcare professional before taking over the counter diet aids or metabolism boosters
What are the complications of obesity?
Although people are often concerned about obesity based on how it affects their appearance, the problem is more than skin deep. Obesity can cause or increase the risk of numerous potentially debilitating or life threatening conditions, including:
– Arthritis
– Hypertension
– High cholesterol
– Heart disease
– Diabetes
– Cancer
People who are overweight or obese get sick more often and die younger than people at healthy weights. For these reasons, it is important to lose excess weight if you are overweight or obese.
Key points
1. Obesity causes or worsens many potentially life threatening conditions.
2. To reduce these risks, it is important to lose excess weight
Fast Facts
– Obesity or overweight are simply defined as weighing too much for your height
– The best ways to determine if you are overweight or obese is to measure your BMI and waist-hip ratio
– Factors that influence obesity include genes, social or cultural influences, and lifestyle issues, such as having the time or desire to cook and eat healthfully and exercise
– To eat healthfully, it is important to understand good nutrition and which foods are healthy or unhealthy
– The main treatment for obesity is to consume fewer calories than you burn, through diet and exercise. The goal is to lose pound per week
– Diets that cause rapid weight loss may not be safe and can be ineffective in the long run
– Medications can cause significant side effects and should be used, under a physician’s supervision, only after diet and exercise has failed
– Over the counter products that promise rapid weight loss may not be safe or effective; always consult with a healthcare professional before taking them
– Surgery is a last resort that carries significant risk; it is reserved for severely overweight people or those whose health is at serious risk due to obesity
Meridia is a registered trademark of Abbott Laboratories, Inc.; Xenical is a registered trademark of Roche Laboratories.
References
Thompson WG, Cook DA, Clark MM et al. Treatment of obesity. Mayo Clin Proc 2007;82(1):93-101.
Yusuf S, Hawken S, Ounpuu S et al. Obesity and the risk of myocardial infarction in 27,000 participants from 52 countries: a case-control study. Lancet 2005;366(9497):1640-9.
Gardner CD, Kiazand A, Alhassan S et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA 2007;297(9):969-77.
Snow V, Barry Patricia, Fitterman N et al. Pharmacologic and Surgical Management of Obesity in Primary Care: A Clinical Practice Guideline from the American College of Physicians. Annals of Internal Medicine 2005;142:525-523.
Obesity. Mayoclinic.com. Available at: http://www.mayoclinic.com/print/obesity/DS00314/DSECTION=all&METHOD=print. Accessed 3/15/07.
Copyright 2007, MD Kiosk
