obesity and weight control for pilots and controllers

Introduction

Many pilots are distressed when they notice that their own centre of gravity is moving considerably further forward than it was when they were just learning to fly. The consequences of pilots reaching a weight they consider gross can be just as hazardous as trying to fly an aircraft that exceeds its gross weight. When pilots can no longer see their own "landing gear" because of the tire around their "fuselage," they look for medical maintenance personnel or decide to perform their own annual inspection and maintenance. This guide is a simplified manual on weight reduction and fat loss. Following the manual may improve your airworthiness, add years to your service life, and dramatically improve your performance.

Costs of Excess Weight

Excess weight is a common health problem in the United States. It may also have adverse social and occupational implications in some individuals. In several occupations, excess weight may be a safety concern. The social and health consequences of excess weight lead to Americans spending over $30 billion each year in medical treatment and over the counter weight loss efforts. Half of American women and a quarter of American men attempt to lose weight each year with variable success over the long term.

Definitions

Although "overweight", "obesity" and the politically correct "gravitationally challenged" terms are often used interchangeably, medical professionals have separate definitions for the first two terms. Obesity is a more severe form of overweight and morbid obesity is the most severe form. Nutritionists point out that someone can be near their ideal body weight and have a "normal" figure, yet be "overfat". These individuals weigh an average amount, but have low lean muscle mass and high percent body fat. Similarly, a bodybuilder may be "overweight" by standard tables, but have a very low body fat percentage, a high lean muscle mass and not be "overfat". For this discussion, the terms overweight, overfat and obese will refer to measures of ideal body weight and body mass index. Many other methods of calculating body fat are available including skin callipers, body circumferences, water immersion, bioelectric impedance and nuclear imaging to name a few.

Understanding Obesity

Obesity (overfat) is a chronic disease that is increasing in the United States. Obesity is associated with many other diseases and makes their consequences worse. Obesity has negative social implications in our current society and sometimes connotes "fault" or lack of control. The cause of a tendency toward obesity is not defined. Intentional weight loss is often temporary and difficult to achieve. Medications to "treat" obesity are fraught with complications. Surgery for the condition also is associated with complications and introduces other medical problems. Nutritional requirements for obese individuals attempting to lose weight have not been well explained.

Ideal Body Weight

Approximately one third of Americans are overfat or obese. The definitions of obesity and overweight are changing. In the past, ideal body weight (IBW) was calculated by a formula based on gender. Some pilots and controllers feel, perhaps correctly, that their Ideal Body Weight is that weight listed on their medical certificate. A somewhat more scientific approach uses a formula derived from insurance company research on longevity. For men, the formula for IBW allows 106 pounds for the first 5 feet of height and 6 pounds per inch above five feet. A 62" inch male would have an IBW = 106 lb. (5) + 84 lb. (14") = 190 lb.. Ten percent leeway on each side of IBW is considered healthy. In the example, our 62" male could weigh 171-209 and still be considered healthy. The formula for women is 100 lb. for the first 5 feet of height and 5 lb. per inch above that height.

Individuals are considered "overweight" if they are greater than 20% over IBW (similar to exceeding the Utility category weight on an aircraft) and "obese" if they were more than 30 percent over IBW (similar to exceeding the Normal category weight). "Morbid obesity" is defined as >200% of IBW. Obviously these formulae do not account for the bodybuilder with 4% body fat or the anorectic young woman with 30% body fat.

Body Mass Index

Recently, the classification of obesity and overweight is moving toward the use of Body Mass Index (BMI). For pilots, think of BMI as similar to C.G. limits on an aircraft and IBW as Gross Weight limitations. A BMI of 25-29.9 is considered overweight and a BMI of 30 or greater is considered obese by some experts. A National Institutes of Health Consensus conference considers obesity to start at a BMI of 27. Morbid obesity is defined as a BMI > 40 kg/m2. The BMI is calculated by using the body weight in kilograms divided by the height in meters squared or BMI = kg/(m2). For weight in kilograms, divide weight in pounds by 2.2. For height in meters, multiply height in inches by 0.0254.

Health Consequences of Obesity

Obesity has recently been listed as a major independent risk factor for heart disease and stroke. Previously, it was considered a minor risk factor associated with many of its other attendant medical problems. Overfat individuals are at significantly increased risk for diabetes, high blood pressure and elevated cholesterol. Cancers including breast, colorectal, prostate and endometrial occur in higher rates of obese individuals. Obesity increases the risk of gall stones and gall bladder disease. Obstructive sleep apnea with respiratory problems, daytime sleepiness, heart disease and reduced mental function, is much higher in obese individuals than those near their ideal body weight. The extra weight that obese individuals carry leads to increased osteoarthritis and back pain. Gout and varicose veins are also complications.

Causes of Obesity

Obesity is a product of genetic predisposition (heredity) and environmental factors. Some individuals have a genetic make up that causes them to store fats easier than others. Although the total number of fat cells is relatively fixed, the size of the cells varies dramatically depending on the amount of fat stored in each cell. Between 30% and 50% of an individual's fat make up is genetically determined.

Environmental factors, such as disease and medications, can influence fat distribution. Thyroid disease directly affects metabolism and weight. Medications such as steroids can cause an increase in central body fat. These are rare causes of obesity.

Calorie Burn Rate - Basal Metabolic Rate

The most significant environmental factor in determining weight is food and calories taken in versus those expended. Even with a genetic tendency toward being overfat, in the absence of more calories taken in than expended, a person will not gain weight.

Calories are a unit of energy and are more correctly expressed as kilocalories (kcal). Food energy is stored in the body as fat, muscle proteins or carbohydrates. For the same amount of weight, fat (9 cal/gram) has more than twice the calories of protein or carbohydrates (sugars and starches, 4 cal/gram).

A key factor in determining how many calories an individual can take in while maintaining weight is the resting metabolic rate (similar to the throttle-idle fuel consumption rate). This determines how many calories a person uses daily without any activity. These calories are expended just by breathing, muscular activity of the heart and other essential functions of living. Resting metabolic rates may vary as much as 400 calories per day in different individuals. Since approximately 3500 calories are equivalent to a pound of fat, 400 calories per day make a three and a half pound difference per week.

The average adult male will burn about 1800-2500 calories with normal activity each day. This includes a resting metabolic rate of about 1200-1500 calories per day and activity calories of 600-1000 per day. Additional exercise may increase this by several hundred calories. Different activities have different "caloric burn rates". Women have rates about 10% less than men. Lean muscle burns calories over 20% more efficiently than fat. Thus a muscular person will burn more calories without any activity than an overweight (overfat) person who has the same weight. Resting caloric rate decreases with age past approximately thirty years in both men and women. Lean muscle mass also decreases with age.

Why Do We Gain Weight?

Why do many people tend to gain weight as they get older? The answer is both simple and complex. The simple answer is that they begin to take in more calories than they use or burn. Assuming the average adult burns 1800-2500 calories a day with minimal activity, an intake of the same amount of calories each day would allow the person to maintain a stable weight.

One pound of fat equals about 3500 calories. Therefore, if a person eats 500 calories per day more than they use up, they will gain one pound per week (500 calories x 7 days = 3500 calories = one pound). As little as 100 calories per day excess intake will result in a ten pound weight gain in one year.

The more complex answer to why we gain weight, particularly with getting older, has to do with changes in the body's physiology. Several changes occur with aging. First, our metabolism slows after age thirty. Our bodies do not burn as many calories with the same amount of activity. Next, we lose lean muscle mass which also burns calories faster than the fat it may be replaced by. Perhaps most importantly, our activity level changes.

Physical activity is the most significant variable in the weight control equation. If 1200-1500 calories are used each day simply by breathing and having a heart beat (basal metabolic rate/BMR), only 500-1000 calories used each day are accounted for by activity of living. People with desk jobs (or flying jobs) and little physical activity may only use 600 calories each day above their basal metabolic rate. Those with moderate activity that requires some walking, such as a fuels handler at an FBO, may use 900 or more additional calories per day. Finally, people with physically demanding jobs, such as baggage handlers, may burn over a thousand calories more than their BMR daily. Obviously, the last group may eat more each day with less risk of gaining weight than the less active groups.

Who Should Lose Weight?

No consensus exists about who should lose weight and how much should be lost. Most medical professionals feel that anyone with obesity (BMI > 30.0 or weight >140% of IBW) should lose weight regardless of their health status to prevent health complications. Individuals with medical complications of being overweight should lose weight if they have a BMI >27.0 or weight > 120% of IBW to treat the complications. Complications include high blood pressure, heart disease, diabetes, high cholesterol and male sex. Some experts include arthritis, gall bladder disease and a family history of some types of cancer.

Many health care providers feel that weight reduction to IBW or a BMI of 22.0-25.0 is the goal for anyone with medical complications of obesity. Preventive medicine advocates are more aggressive in their recommendations. Maintenance of IBW for all individuals is the goal, though somewhat unrealistic for an entire population.

Remember that not all people who exceed their IBW are overfat and some people who maintain an IBW are still overfat. An assessment of percent body fat is more appropriate in determining weight control recommendations for those with unusual body types.

Medical research has identified higher risk patterns of obesity. Those people with fat distributed around their abdomens (called "apples") are at higher risk for complications and death than those with the same amount of fat distributed around their hips (known as "pears"). Men with abdominal circumferences of greater than 34 inches or a waist to hip ratio of 1.0 and women with a waist circumference of more than 31" and a waist to hip ratio of greater than 0.8 are at higher risk for complications due to fat distribution.

Can I Lose Weight in Just One Area?

No. Many people feel that only one or two parts of their bodies have too much fat, such as thighs or the abdomen. Advertisers tout rubber wraps and cellulite pills to improve the appearance of a particular area. These don't work. A person losing fat does so equally across all parts of their body as percent body fat decreases. The muscle tone in a particular area may be toned through exercise targeted at that area to improve appearance. An example would be sit ups for a flatter stomach. The muscles of the body are generally covered by fat, so toned muscles with lots of fat over them still appear fat.

Is Losing Weight and Regaining It Unhealthy?

Recent articles have raised concern about the health effects of repeated weight loss and gain, also known as weight cycling. Scientific evidence does not demonstrate any increased risk of weight cycling over maintenance of a stable overweight status. In a large study of 28,000 women, weight loss, even temporarily, reduced risks of disease. A 20 pound weight loss lowered deaths from all causes, heart disease and cancer by 25%. In a smaller study of 15,000 women, ANY weight loss reduced heart disease by 10%, deaths by 20%, deaths from diabetes by 30-40% and from breast cancer by 40-50%.

How To Lose Weight

Sustained weight loss takes commitment, persistence and patience. Any program to lose weight permanently will not happen fast. It involves a multi-faceted approach of behaviour modification, healthy nutrition, sensible dieting and physical activity. Medications are effective only temporarily and do not change long term behaviour. Nearly all medications used for weight loss are disqualifying for flying and controlling. Surgery should be reserved for the morbidly obese, but may have significant complications that may interfere with safety sensitive duties. For a downloadable pamphlet from shape Up America!, see Healthy Weight, Healthy Living.

Behaviour Modification

Most overweight people feel guilty about what they eat, particularly if they know what they are eating is high in calories. This triggers feeling of self-criticism and a defeatist attitude about commitment to weight loss. A more healthy attitude would include a recognition that weight loss takes persistence and involves tradeoffs of food and exercise to burn off calories. Eating an extra piece of pie containing 300 calories won't hurt a weight loss program if 300 calories of extra exercise (walking or running about 3 miles) is included. That is a lot of work, however, for the several minutes it takes to eat one piece of pie.

Support of family members and friends in a weight loss program is very helpful. Temptations are resisted more easily if someone helps remind you of alternatives or will share a commitment to a joint exercise program. Tracking calories in food and exercise through a diet and activity log will help explain progress or lack of progress in a weight reduction program. Habit patterns of eating in various situations are similar to addictions of smoking or alcohol. Recognizing the triggers for food snacking or bingeing is an important step in interrupting the behaviour. Designing alternate activities or substituting nearly calorie-free food, such as raw vegetables, for calorie dense snacks will lower daily caloric intake. Avoiding buying food that is high in calories will eliminate some choices. Shopping on the outside aisles of a supermarket where healthy food (except ice cream and cheese) is located, as opposed to the inner aisles where calorie-dense processed food is found, will help.

The major principle in sustained weight loss is a commitment to establishing behaviour modifications that cause permanent lifestyle changes, not temporary interruptions in unhealthy habits.

Dieting

Thousands of weight reduction diets are touted as the answer to permanent weight loss. If there was a single successful diet plan, its advantages would spread rapidly through the public and would quickly outsell all others. No such miracle diet exists. Instead, this article will offer some sensible guidelines and comment on the potential hazards of some popular diets.

Nutrition occurs on two levels, the macronutrient and the micronutrient levels. Macronutrients for the body are oxygen, water, protein, fat and carbohydrates. All are absolutely essential for the body to function, even fat. The macronutrient requirements are fairly well defined and quantifiable. Recent legislation mandates quantifying macronutrient information on all food labels for consumer use.

Micronutrients include vitamins, minerals, trace elements and plant products. These micronutrients are less well studied and requirements are currently not well quantified for optimum health. Most of the vitamins and a few of the minerals have Recommended Daily Allowances (RDA) established by the Food and Drug Administration (FDA). RDA's are minimal amounts required in the average person on an average diet to avoid overt disease.

For optimum health, people on a reduced diet or with increased needs, such as illness, pregnancy, cancer or heavy exercise, may have significantly higher requirements for optimum health than the RDA. See our article on Nutrition and Heart Disease Prevention and our article on Vitamins & Minerals.

General Rules for Dieting

Some general rules apply to all diets. First caloric intake for weight maintenance should be approximately 30 calories per kilogram of IBW or 13 calories per pound. Calorie intake should be reduced by 500 calories per day for each pound per week of weight loss desired. The minimum calorie intake to obtain adequate nutrition from food sources varies with individuals. Estimates range from 800 to 1500 calories. Dieters should consider micronutrient supplementation to maintain optimum health during periods of calorie restriction.

Next, healthy diets should contain elements form all of the macronutrient groups. Approximately 20% of calories should come from fats, preferably from mono- and poly-unsaturated fats to protect against heart disease. Fats are essential in many functions of the body, such as hormone production. Protein should make up 15-25% of the diet. Protein may come from animal sources (preferably fish, fowl or lean meat to avoid saturated fats), non-fat dairy products (egg whites, milk and cheese in moderation) or plant sources, which are the healthier alternatives. These plant sources include beans and soy products. Fibre and water are also important components of a healthy weight reduction diet. Both increase satiety, or a sense of fullness and decreased hunger. Water has no calories and many high fibre foods and products are nutrient dense with few calories. Fibre also helps bind fat in the intestines and slow absorption of the fat.

Many highly touted weight reduction diets are unhealthy or dangerous. Single food diets are nutritionally bankrupt and may cause problems with gall bladder disease. Very low calorie diets have some of the same problems. Diets that avoid single macronutrients such as fats, protein or carbohydrates tend to be nutritionally depleted also. Long term success with weight control is best achieved with a healthy, nutritionally balanced diet that is enjoyable and sustainable. See an article in the Federal Air Surgeon's Medical Bulletin, Fall 2000 on the subject of fad diets, In Dieting, You Can't Fool Mother Nature by Glenn Stoutt, MD.

A review of low-fat diets versus low-calorie (low-carbohydrate) diets showed no significant difference in weight loss over 18 months. See the Cochrane for Clinicians: Putting Evidence into Practice article from American Family Physician for more details.

Dieting Strategies

It is important to eat three or more small meals per day. One popular misconception about dieting and calorie reduction is that skipping meals will reduce calorie intake and make you lose weight fast. In the short term, you may lose weight, but your body undergoes several changes that make sustained weight loss difficult and unhealthy. First, the metabolism changes to allow the body to convert muscle and sugars into fat making it an efficient fat storage organism. This is to avoid the periods of starvation induced by skipping meals. Second, the body breaks down muscle for energy instead of using the muscle to burn fat. Third, the wide fluctuations in blood sugar levels trigger hunger and eating. Finally, the sustained nutritional needs of the body are not met.

By eating regularly in small amounts, the body has a constant supply of energy. The sugars in the body are used and muscle is preserved. Blood sugar levels are relatively even and hunger attacks are eliminated. If the diet includes significant water and fibre, a person won't sense an empty stomach.

Dieting Strategies for Pilots

Many people have lifestyles that are not conducive to regular healthy, low calorie meals. Airline and commercial pilots are prime examples. Food is not available at regular intervals. When it is available on the road, it may be high calorie/high fat/low nutrient density food. Snacking in between meals is common. Several strategies exist to help manage weight and obtain appropriate nutrition in this challenging environment.

First, attempt to eat a healthy breakfast that avoids high sugar foods or excess amounts of sweet fruits. These will trigger a rise in blood sugar for several hours followed by a precipitous drop. The dropping blood sugar triggers hunger impulses and food cravings three to four hours after the meal. Complex carbohydrates such as breads, grains, bagels (with jams rather than butter or cream cheese), oatmeal and other starches will provide a flatter, sustained level of blood sugar for longer periods.

Proteins and fats will also give similar results, but may be difficult to find in low calorie forms for breakfast. Sausage and bacon is not a healthy choice for protein, but eggs may be an alternate source if cholesterol is not a problem. For those who can tolerate milk products, yogurt with grains, such as grape nuts or wheat germ mixed in, offers an excellent source of slowly delivered, nutrient-rich calories. Low sugar fruits such as melons, provide vitamins, minerals and fibre in a healthy form.

Next, drink plenty of water during the flight. Water will keep the stomach full, aid in elimination, prevent dehydration and not add any calories. Three or more quarts of water daily will be helpful. Often, having a water bottle available in the cockpit and refilling as necessary will make obtaining that amount relatively easy. Coffee with cream and sugar consumed regularly during flight adds tremendously to daily calorie intake. Non-diet soft drinks and fruit juices made from concentrates also add to the daily calorie load without significant nutrient value. Fruit juices made from concentrates also add to the daily calorie load without significant nutrient value, other than added vitamin C.

Snacking on dried fruit, which can be stored without refrigeration in zip-lock bags, provides a nutrient and fibre rich substitute for high calorie snacks. If sustained periods of flight without access to healthy food is anticipated, a powdered nutritional dietary supplement that can be mixed with water will eliminate hunger for several hours. When stored in resalable plastic bags or individual serving containers, they require minimal storage space. They also provide an acceptable substitute for breakfast. Manufactured or processed food that frequently comes in plastic wrapping often is high in fat, calories and salt. Snacking on fresh vegetables is a very low calorie source of fibre and nutrition for those who do not have to fly on multi-day trips away from a grocery store.

Several small snacks will maintain blood sugar levels and decrease calorie absorption more efficiently than occasional large meals. In between these large meals, the body goes into a relative state of starvation. This state increases hunger and triggers physiologic changes in the body that increase fat storage and calorie absorption. Probably the most tempting source of unlimited high calories is a visit to a buffet for dinner. Try to focus on ordering healthy, low fat food from a menu and drinking plenty of water with a meal. For those who must have dessert, fruit or sorbet offers low fat alternatives.

Avoid fast foods that are heavily laden with fats and calories. Although convenient, most foods from fast food restaurants are nutritionally deficient, high in salt and often supply a day's worth of calories in a single meal. Tables exist to count fast food calories easily.

Don't smoke to avoid eating. The risks of smoking outweigh (no pun intended) the risks of being overfat in the over all health picture.

Finally, avoid alcohol. Alcohol in any form is a very high calorie source with little or no nutrient value. Red wine and small amounts of alcohol may add some degree of protection against heart disease, but any benefit gained is less than the penalty paid for the individual trying to lose weight. For those not concerned with excess weight, small amounts of alcohol may be beneficial.

For more information on dieting and weight management strategies, contact a preventive medicine specialist.

Exercise

The third leg of a weight control program relies on regular exercise to increase calorie expenditure. A nutritionally responsible method for weight reduction includes eating adequate amounts of the proper foods and exercising to burn the extra calories form these foods. A person who exercises regularly can afford to eat several hundred calories a day more than their non-exercising friends without incurring a weight gain. See the Virtual Flight Surgeons article on Fitness Assessment and Exercise Recommendations for more information on this subject

Exercise is categorized in two basic forms, aerobic and anaerobic. Aerobic involves sustained activity of 20-30 minutes or more duration with an increase in heart rate to 70% or more of the predicted maximum. This type of activity has proven to be useful in reducing heart disease, stroke and other cardiovascular diseases, lowering cholesterol and blood pressure, improving blood sugar control in diabetics and improving mood. Examples include, running, walking, cycling, swimming, cross country skiing, rowing and many others. The disadvantage of aerobic activity is that the number of calories consumed is relatively small for the time expended, unless the intensity level is very high. However, aerobic activity uses fat as a fuel and is an excellent way to lose body fat.

Anaerobic activity involves short bursts of intense activity, usually involving some form of resistance. Weight training is the classic example. Weight training and other resistance exercise increases lean muscle mass. This will increase the baseline metabolic rate and resting caloric usage. Calories consumed during anaerobic activity come primarily from stored sugars in the body and is not as efficient in burning fat as aerobic exercise. Because muscle weighs more than fat, people losing fat and increasing muscle mass may not see a rapid reduction in weight. Muscle tone will improve, however, and percent body fat will decrease. Resistance training slows the progression of osteoporosis in both men and women and increases strength. Astronauts engage in resistance exercise during long duration space flight to minimize the rapid bone loss that occurs in a weightless environment. Many team sports such as basketball and soccer combine elements of both aerobic and anaerobic activity.

Both of these forms of activity consume calories and are useful in a weight reduction program. The level of calorie consumption depends on the intensity and duration of exercise. In general, walking and running one mile uses about 100 calories. Runners just burn the 100 calories faster than walkers who cover the same distance. Swimming 300 yards and bicycling approximately three miles also burns about 100 calories.

Many pieces of modern exercise equipment found in health clubs will quantify calories used. These numbers are not extremely accurate unless your weight is used in the calculations or you weigh about 160 pounds (average healthy weight for a 5'10" male used to program exercise equipment). Weight lifting consumes a highly variable number of calories depending on the amount of weight lifted and number of repetitions. Many resources are available for calculating calories used for specific activities. About 500 calories per day of added exercise are required to lose one pound per week if weight was stable before starting an exercise program.

Other forms of activity, such as yoga or tai chi, increase flexibility and improve mental function, but are not significant sources of calorie expenditure.

It is important to find one or more activities that are enjoyable to participate in. Exercise is a key element of a weight reduction program, but if it is not enjoyable, it will not be sustained. Many people keep their interest in exercise high by switching activities periodically. Weather and availability of exercise facilities may force people to be involved in several activities to maintain a regular exercise program. Certainly a piece of home exercise equipment such as a treadmill, exercise cycle or rowing machine is convenient. When on the road, many pilots find it difficult to exercise. Walking in the terminal, while not a method to increase strength, will consume some calories. This is particularly true if walking is done instead of eating. For other hints on exercise during a busy day without the benefit of a health club, see Fitting Fitness In from Shape Up America!

Many people try to exercise with rubber suits or heavy clothing to increase water loss from the body. A false sense of rapid weight loss is gained if a person weighs themselves immediately after exercising and before rehydrating. Weight loss due to water is very transient and is reversed as soon as the person consumes fluids again. The risk of heat exhaustion or heat stroke with loss of consciousness makes exercising with these suits very dangerous medically. This is also very dangerous administratively for pilots/controllers who may have to undergo extensive and expensive testing to maintain their medical certificate if they lose consciousness while exercising. Exercise in clothing that allows you to remain as cool as possible and stay well hydrated when exercising.

Fitness

Exercise increases physical fitness and mental well-being. Measures of fitness should not be limited to single categories. Aerobically fit individuals may not be able to lift relatively light loads. Muscular individuals with very low body fat percentage may not be able to reach their toes or jog more than a few minutes. Useful fitness assessments should include evaluations of cardiovascular conditioning, strength, flexibility and body fat percentage. Comprehensive personal fitness assessments are available at some health clubs or through commercially available self-assessment products. We recommend the educational, scientifically based and easy to understand Fitness Age assessment tool. See the VFS Fitness and Exercise article for expanded discussions and resources.

Medications for Weight Loss

Many overweight people experience intense cravings for food and feel the need for medications to suppress their appetite. Several prescription medications are available as well as several over-the counter medications. The medications are effective in suppressing appetites as long as a person remains on the medication. Once discontinuing the medications, appetite returns and so does the weight. Medications are rarely effective in establishing permanent lifestyle modifications required to sustain weight loss in a healthy manner.

The National Institutes of Health recommends considering weight reduction medications only if a person has a BMI > 30 or greater than 27 with obesity related co-morbidities or other diseases. In the book Clinical Evidence: A Publication of BMJ Publishing Group, a chapter on Obesity contains a listing of the effects of drug treatments for obesity in adults.

For pilots and controllers, most prescription weight loss medications are not allowed. Many are related to the amphetamine category of drugs. See the article "Weight and Balance, Diet Pills and Flying," by Drs. Donato Borillo and David Lozano in the Federal Air Surgeon's Medical bulletin on prescription weight loss medications and aeromedical certification. Most medications are not recommended for periods longer than 12 weeks.

Recent research has shown that the weight loss combination known as Fen-Phen can cause serious heart valve abnormalities, even when used as prescribed. The risk of severe lung problems also exists with these medications. As a consequence, they have been removed form the market. Other similar weight reduction medications not approved by the FAA include Bontril (phendimetrazine), Tenuate (diethylproprion), Mazanor (mazindol), Fastin and Ionamin (both phenteramine).

A new weight reduction medication of the same category has been approved by the FDA. It is called Meridia (sibutramine). Meridia is also a controlled drug that is prohibited for use when flying or controlling. The maximum duration of therapy for this medication is 12 weeks. Sustained weight loss past this period is rare. It is currently not approved by the FAA. See FDA Meridia Press Release.

Xenical (orlistat): A "fat blocking" lipase inhibitor reduces weight by blocking the absorption of fat from the intestine by 1/3, thus reducing calories absorbed from the intestines is approved by the FAA for use. Prior to flying/controlling on the medication, individuals must demonstrate two weeks of use without significant side effects. The major side effects are flatulence, greasy smelly stools and urgent bowel movements. These side effects may compromise flying safety or worsen with increasing altitudes. The medication may also interfere with the absorption of fat soluble vitamins and supplementation with vitamins A, E and K may be recommended. View FDA Xenical Consumer Information Page (Adobe Acrobat required). See manufacturer info.

Because of significant complications and deaths in older people using "herbal fen-phen" or ephedra, acompound very closely related to the pseudoephedrine found in over the counter cold preparations such as Sudafed, these medications have been withdrawn from the market. Medications containing ephedra are not approved by the FAA.

Another non-prescription medication found in cold medications, phenylpropanolamine or PPA, is used in some of the common diet pills. It has the same potential complications as ephedra. The FDA has issued a recall of all products containing PPA due to documented cardiac deaths.

Newer anti-depressant medications, the Selective Serotonin Reuptake Inhibitors (SSRI's) including Prozac, have a side effect of weight loss. The presumed mechanism is boosting brain levels of serotonin to suppress appetite and cravings. currently, no anti-depressant medications are authorized by the FAA for pilots or controllers holding medical certificates. Some research indicates that several over-the-counter nutritional supplements that boost serotonin levels in the brain, may have similar effects. These are not currently regulated by the FDA or restricted by the FAA. Pilots/controllers should use these products with caution to determine there are no side effects.

The bottom line for all weight loss medications is that the effects are not permanent because, if used independently of a comprehensive weight management program, they do not modify behavior long-term and that they are potentially dangerous from both health and medical certification considerations.

The journal American Family Physician published an excellent article, on Drug Therapy for Obesity, for people wanting more information on the subject. A second article addresses the ineffectiveness of Common Dietary Supplements for Weight Loss.

Surgery for Weight Loss

Two broad categories of surgery exist to help overfat people. One, liposuction, is simply a cosmetic procedure designed to remove some accumulated fat from a particular portion of the body. The second category, called bariatric surgery, involves by-passing a part of the stomach or intestines to limit the amount of food a person can eat and absorb.

Both surgeries have the potential for very serious complications. Liposuction does nothing to modify behavior and does not result in long term weight or fat reduction. Some gastric bypass operations are associated with nutritional deficiencies and "dumping syndromes" or chronic diarrhea. These operations are more successful in long term weight reduction. The surgery is usually reserved for people with a BMI > 35 with medical complications of obesity or for the morbidly obese individual with a BMI > 40. See an article from the Winter 2002 Federal Air Surgeon's Medical Bulletin, Medical Certification After Bariatric Surgery by Donato J. Borrillo, MD, JD.

Liposuction has also been used to reduce fat in selected areas of the body. In this technique, a hollow catheter is inserted under the skin to remove fatty tissue by suction. Significant amounts of blood and fluid can be lost if the liposuction is not performed correctly. See The New England Journal of Medicine article on deaths due to liposuction in New York City. Liposuction is not disqualifying for FAA medical certification after the individual has been released to return to full activity.

Summary

Obesity and being overfat are serious risks to health. Effective strategies for achieving healthy and desired weight and body fat depend on a long-term commitment to changing behaviour. Three major elements in a weight reduction program include behaviour modification and support, calorie reduction through regular intake of limited amounts of nutrition rich foods and regular exercise. Nutritional supplementation may be useful for those who can not eat healthy foods at every meal. Water and fibre intake are important adjuncts to avoid hunger. Medications have potentially harmful side effects, generally only work while taking them and are not allowed by the FAA for pilots/controllers. Surgery is appropriate only in extreme cases that have failed other methods to control fat and weight. Success takes time and persistence. The rewards of achieving and maintaining a healthy body fat percentage extend beyond physical and emotional health. Pilots, like aircraft, will perform best with a desirable centre of gravity, takeoff weight far below the maximum gross weight, high quality fuel without contaminants, avoidance of prolonged periods on the tarmac without flight and regular maintenance and inspections. May your flight through life be a healthy and safe one.
Healthy Weight Loss Checklist - A 12 Step Program

1 Commit to a weight loss program and stay with it
2 Analyze your body fat, BMI, weight and IBW
3 Learn how count calories and read food labels
4 Define daily calorie intake goals for weight loss
5 Eat lots of high fibre foods (25-30 grams/day)
6 Drink lots of water (1 oz/kg of body weight/day)
7 Eat grains, starches, fruits, vegetables, lean meats
8 Avoid dairy products, except non-fat types
9 Avoid Consider nutritional supplements for aggressive diets
10 Avoid sweats, simple sugars, alcohol, soft drinks
11 EXERCISE DAILY in moderation
12 Stay with the program, check weight only monthly