We idolize people who are the thinnest of the thin-the thinnest five to ten percent of our population. It’s ironic that we’re also a nation of “super-sized” portions. The average portion size at a U.S. restaurant is more than 25% larger than our European counterparts.

Unfortunately, 64% of the American public is overweight and 33% of Americans are obese. Weight loss and maintenance are cornerstones of good health and happy living. Obesity is associated with type 2 diabetes, heart disease, stroke, cancer, obstructive sleep apnea, depressed mood, and more. For most, weight loss and weight management should be realities of life.

But for many a desire to lose weight or maintain weight loss doesn’t necessarily dictate success. Weight loss and weight maintenance are tough work and successful strategies vary based on how much weight a person needs to lose. Some people can succeed with diet and exercise alone, others need more invasive interventions like surgery. And even for those who are lucky enough to realize their desired weight, maintenance, although more straight-forward, can be even more difficult than the initial weight loss.

Weight loss: diet and exercise

The status of a person’s weight is best determined by their Body Mass Index (BMI). BMI is a calculation derived from dividing a person’s weight in kilograms by their height in meters squared. For the calculation-averse, a BMI calculator is available on the National Institutes of Health website.

According to the Department of Health and Human Services, people with BMI’s between 18.5 and 24.9 are considered normal weight. People with BMI’s between 25 and 29.9 are considered overweight. Those with BMI’s between 30 and 39.9 are classified as obese. Finally, people with BMI’s greater than 40 are categorized as morbidly obese.

For Americans who are simply overweight, self-control measures are a good place to start. Medical intervention is best reserved for obese individuals or overweight people who have medical problems or have failed self-managed diets on numerous occasions. Although exercise is important in any weight loss or weight maintenance regimen, research shows that diet is the most effective means of weight loss. A successful diet is a diet which is both balanced and calorically-restricted.

What does “calorically-restricted” mean? Everybody has a distinctive Basal Metabolic Rate (BMR). BMR is defined as the minimum number of calories needed to maintain life activity at rest. It varies based on age, activity level, genetics and sex (men have higher BMR’s than women). For example, a Mr. Universe body builder has a BMR that may be several times that of a bed-ridden senior citizen. In order to lose weight, a person must consume fewer calories than their BMR or maintain a diet equal to their minimum caloric requirements and burn off enough calories exercising to undercut their BMR.

According to the USDA, a balanced, calorically adequate diet that best approximates the BMR of an average American includes: 6-7 ounces of breads, cereal, rice and grain; 2 cups of fruit, 3 cups from the milk category, and about 6 ounces of meat, fish, nuts, poultry and beans. The USDA has developed resources that help people determine a diet which best approximates their own individual BMR based on their height and weight. These resources can be found at http://www.mypyramid.gov.

All diets must be balanced because despite equivalent calorie counts not all types of food are equal. For example, a calorically-balanced diet high in trans-fats can damage the heart and facilitate the conversion of dietary fat to body fat. A balanced diet is a diet high in fiber (fresh fruits and vegetable) and low in saturated or animal fat. Trans-fats, often found in fast and junk foods, should be avoided altogether.

So what about diets like the Atkins or South Beach? Fad diets like the Atkins or South Beach normally serve as quick-fix panaceas. Few if any dieters can sustain the weight lost from such drastic dietary change. For many, eating only meats and proteins can only last so long before it’s back to the cookies and cakes. Health researchers have found that people can only restrict their eating patterns for a short period of time before they crave the variety of a more balanced diet.

For overweight people intent on losing weight, exercise is also important. Exercise is the “yin” to diet’s “yang.” Exercise increases a person’s BMR, maintains lean muscle, improves mood, burns off calories, and prevents disease such as diabetes and high cholesterol. Any exercise program should take into account the health and physical conditions of the person planning to work out. A good place for most people to start is walking between 150 and 200 minutes a week (30 minutes a day).

There’s a certain psychology of weight loss. Taking advantage of how we perceive our world can facilitate our desire to lose weight. Health psychologists and weight loss experts have devoted lifetimes to studying what works and what doesn’t. The following are just a few pointers from a long list of useful “mind tricks:”

* Logs and contracts: All people intent on losing weight should keep logs of how much they eat and how much they exercise. Logs help put everything in perspective and help dieters plan out what they need to do. Diet and exercise contracts also help people lose weight. By writing a contract in concise and specific language, people make an obligation to themselves or others (for example another like-minded dieter) to devote themselves to losing weight.

* Stimulus control: Certain environments serve as keys or triggers to eat mindlessly. Good examples of mindless eating environments include sitting in front of the television watching “American Idol” or playing video games. Dieters should limit eating to one area of the house like the kitchen or dining room.

* Altering the act of eating: Most people eat too fast. By consuming food quickly, people end up not realizing that they’re already full. It’s important for dieters to slow down and enjoy their food.

* Social support: No dieter is an island. It’s best to enlist the help of friends and family when losing weight.

But inevitably most diets fail. People often underestimate their caloric intake and strive for unattainable weight loss goals. Worst of all, dieters oftentimes end up gaining back weight in excess of what they lost. Many people develop an unhealthy history of failed diets and chronic weight loss and weight gain (“yo-yo dieting”). For some failed dieters, more intensive methods of diet and weight loss are beneficial, like Weight Watchers or medical supervision by a physician or health care professional. Others may need to pursue more invasive interventions.

Weight loss: pills and “going under the knife”

Many people never achieve desired health and cosmetic effects from diet and exercise alone. There are other options.

Certain obese people with BMI’s between 30 and 40 are eligible for drug (medication) therapy. “Pills” include antidepressants, stimulants and medications like Orlistat which decreases the absorption of dietary fat. At best, medication only results in moderate weight loss ranging from 10 to 15 percent and ceases once a patient stops taking the drugs. Furthermore, all medications have side effects and weight loss pills are no different. For example, because of their high addiction-potential, stimulants are only recommended for short-term use.

Bariatric surgery is the best option for people who are morbidly obese (BMI’s greater than 40) or people who are obese with BMI’s greater than 35 and have medical problems such as diabetes, sleep apnea or coronary artery disease. Bariatric surgery has proven to curb medical conditions such as diabetes, heart disease and sleep apnea and drastically improve quality of life. There are two types of bariatric surgery: restrictive and malabsorptive.

Restrictive bariatric surgical procedures such as the gastric laparoscopic band (LAP-BAND) are becoming the most popular option for most morbidly obese patients. Restrictive bariatric procedures reduce the volume of the stomach and cause people to feel fuller faster. The LAP-BAND surgery involves placement of an adjustable band around the top of the stomach by a highly-qualified surgeon. Procedures such as the LAP-BAND have few medical repercussions and less than one percent of all people undergoing such procedures die afterwards. Qualification for the LAP-BAND isn’t easy and varies by insurance carrier, but most insurance carriers require a history of failed attempts at diet and exercise and a battery of health visits with nutritionists, psychiatrists and other health professionals.