Obesity and Weight Management
What is obesity and how do we measure its impact on health?
Obesity is an excess of body fat. Although several sophisticated tools can accurately measure body
composition, obesity is defined most commonly by the body mass index (BMI).The BMI is the weight
divided by the height squared in the metric system:kilograms per square meter.BMI correlates very closely
with total body fat and with obesity-related illnesses and excess mortality.A BMI less than 18.5 kg/m2 is
underweight, 18.5-24.9 kg/m2 is normal, 25.0 - 29.9 kg/m2 is overweight, and greater than or equal to30.0
kg/m2 is obesity.In the United States, approximately 30% of adults are obese and another 35% are
overweight.
The impact of obesity on health is affected by several factors in addition to BMI.These include: the total
amount of excess fat; the location of excess fat; an individual's age, race, and ethnicity; the presence or
absence of obesity-related metabolic abnormalities, and; an individual's level of fitness.As might be
expected, severe obesity (BMI greater than 40 kg/m2) is associated with more obesity-related illnesses and
premature mortality than less severe obesity BMI (30-39.9 kg.m2).In general, excess fat in the upper body,
and particularly in the abdominal cavity surrounding vital organs, is associated with more obesity-related
abnormalities than is excess fat in the lower body and fat located just under the skin.
Age is an important predictor of the impact of obesity on health.Overweight children and adolescents have
an increased risk of becoming obese as adults. Metabolic abnormalities are less common than in adults, but
as obesity in children has become more common so have obesity-related illnesses, including diabetes
mellitus type 2.The impact of obesity in adults increases with age, until about age 80.Severe obesity is a less
common cause of premature death in the elderly.By the ninth decade, being underweight is actually a more
important predictor of excess mortality. Race and ethnicity may also play a role. For example, Asians with
only modest amounts of excess fat may have more health consequences than individuals from other
backgrounds with a similar BMI.Conversely, African-Americans can have higher BMIs and still have
weights associated with the lowest risk of illness.
Individuals with equal BMIs may also have different risks of developing obesity-related metabolic
abnormalities and metabolic illnesses.This is most likely due to genetic factors that are not yet fully
identified. For example, some overweight individuals may have significant abnormalities in their blood
lipids, blood pressure, and blood sugar while other individuals with an identical BMI might not.
An individual's ability to exercise (their -fitness-) is also an important predictor of illness and early death in
overweight and obese individuals.Individuals who are sedentary and not -fit- are more likely to develop
obesity-related illnesses and early death than those who are fit.Those that are both obese and not fit have an
even greater risk.Most interestingly, however, individuals who are obese but able to exercise effectively
have a markedly reduced risk.This relationship between fitness and obesity will be discussed in greater
detail below.
Obesity is associated with illnesses that affect almost every body system.These include coronary heart
disease (the cause of most excess mortality associated with obesity), certain cancers (colon, ovary, and
breast), diabetes mellitus type 2, hypertension, lipid disorders, and the metabolic syndrome.Obesity is also
commonly associated with degenerative joint disease (of weight bearing joints), diseases of the
gastrointestinal tract including gastroesophageal reflux disease (GERD) and gallbladder disease,
thromboembolic disorders, cerebrovascular diseases, congestive heart failure, respiratory impairment
including sleep apnea, and a variety of disorders of the skin.Obesity is also associated with a greater risk of
surgical and obstetric complications. Major depression and binge eating disorder are also more common in
the obese. Several studies suggest a greater risk of social discrimination in the obese than in individuals of
normal weight.Of note, osteoporosis is less common in the obese.
The marked increase in the prevalence of obesity in the United States and most other parts of the world is
associated with a marked increase in obesity-related illnesses, particularly diabetes mellitus type 2.
However, recent studies published by the Centers for Disease Control (CDC) using data from the National
Health and Examination Study (NHANES) have suggested that the impact in an individual person with
obesity may be less severe than previously estimated.1On average, a BMI of 30 - 34.9 kg/m2 is associated
with a 20% increase in mortality from all causes and a BMI between 35-39.9 kg/m2 is associated with an
80% increase. These authors have also suggested that being overweight, BMI 25.0 - 29.9 kg/m2, is not
associated with excess mortality at all.
Dr. Baron's Clinical Pearls:Weigh yourself regularly (at least weekly) to define your BMI and to detect
changes in weight over time. If you are gaining weight, have a physician evaluate you for other illnesses,
particularly endocrine disorders such as hypothyroidism, that may be responsible.These are uncommon as an
explanation for weight gain, but they are important and treatable. More common causes of obesity are major
depression, several commonly used medications, and smoking cessation. Have a physician also evaluate
your risk of obesity-related metabolic abnormalities.Evaluation should include a measurement of your waste
circumference, careful blood pressure measurement, and a blood test that includes fasting lipids (low-density
cholesterol (LDL), high-density cholesterol (HDL), and blood triglycerides) and a fasting blood sugar.
Discuss your exercise patterns with your physician.A formal exercise test can also be performed, but this is
typically not required to determine your level of fitness.
Deciding to Lose Weight
Once obese, it is difficult, albeit clearly possible, to return to a normal body weight.Thus, prevention of
obesity should be the priority for both individuals and for society at large. Unfortunately, in most Western
cultures the availability of calories and obstacles to energy expenditure are overwhelmingly common.
Without a conscious strategy to maintain one's weight, it is common to gain weight as one ages. Principles
discussed below associated with successful weight maintenance should also be used by those who have
never been overweight to prevent unintended weight gain.
Although a return to normal weight is uncommon, most obesity-related disorders will benefit from modest
amounts of weight loss. It has been estimated that weight loss of 5-10% of initial weight together with
increases in physical activity can decrease the risk of diabetes and other illnesses in half.Thus, weight loss
(and increases in physical activity) can be seen as a treatment option for almost any obesity-related
disorder.Many individuals will also desire weight loss for psychological, social, or cosmetic
reasons.Selecting a specific weight loss strategy should include a balance of the benefits and potential harms
in each instance.
Not all individuals who would benefit from weight loss are -ready- to change behavior. Readiness to change
can be assessed with the Transtheoretical Model of Change (also commonly called the Stages of Change
model). Although initially developed for use in smoking cessation, this approach is also useful in changing
eating and exercise behaviors. In this model, individuals can be identified as being in one of various stages
associated with behavioral change:precontemplation, contemplation, preparation, action, maintenance, and
relapse. Different behavioral change strategies can be applied during each stage in an attempt to move
individuals to the next stage.
Dr. Baron's Clinical Pearls:Not all patients who are overweight or obese need to lose weight. The decision to
lose weight should be based on the benefits of weight loss and the risks associated with the attempt.For
example, strategies that include diet and increases in physical activity are low risk and can be applied
broadly, whereas others strategies, such as surgery, have greater risk and should be used less often. In
addition to the medical and psychological aspects of a decision to lose weight, individuals must assess their
readiness to change.For most individuals, a strategy to maintain one's current weight and increase one's level
of physical fitness is a reasonable and sufficiently ambitious goal.
Weight Loss Diets
The goal of any weight loss diet is to achieve a daily energy intake that is lower than daily energy
expenditure. Daily energy expenditure can be estimated utilizing common formulas based on age, gender,
and height. Adjustments can be made based on physical activity. A useful web site to help calculate energy
expenditure and develop personalized eating plans has been developed by the United States Department of
Agriculture at .
Most weight loss programs try to create a daily deficit of 500 calories.Because a pound of fat is equivalent
to 3500 calories, this deficit will result in a weight loss of one pound per week. For example, a person who
requires 1800 calories per day to maintain their current weight would need to ingest 1300 calories per day in
order to lose one pound per week.
Studies of weight loss diets, most often done in University-based programs, typically suggest an average
weight loss of between five and ten percent of the starting weight in six to 12 months of follow-up. That is, a
person starting a diet at 200 pounds will lose between 10 and 20 pounds. All studies, however, show a wide
variation among individuals.While many patients are near the average, some patients lose substantially
more. Adherence to the diet program is a more important predictor of success than the diet composition or
type.Community-based programs are also associated with successful weight loss with wide variation among
individuals.Weight Watchers, for example, has reported a 3.2% average weight loss with two years of
follow-up.2
Much of the controversy about weight loss diets over the last several years has focused on the ideal
macronutrient composition (proportion of fat, carbohydrate, and protein) of the diets.In fact, differences in
macronutrient composition have been the basis of popular weight loss diets for decades, particularly diets
that have advocated low intakes of carbohydrates.
Traditionally, recommendations for weight loss diets have paralleled those for weight maintenance and -
healthy diets.-Such diets have traditionally recommended lower fat intakes as the primary macronutrient
strategy for achieving lower calories. Although recommendations have been somewhat liberalized in the last
several years, current Dietary Guidelines (www.health.gov/DietaryGuidelines) published by the U.S.
Department of Health and Human Services and the Department of Agriculture continue to recommend fat
intakes between 20-35% of total calories along with carbohydrate and protein intakes of 45-65% and 20-
35% of total calories respectively.This macronutrient composition is also consistent with the DASH Eating
Plan originally developed for treating high blood pressure as well as with diets recommended for treatment
of lipid disorders and diabetes.Most vegetarian diets andMediterranean-style diets also fall within this range
and can be designed to achieve an energy deficit for weight loss.
A key feature of macronutrient-balanced weight loss diets is close attention to portion size.The marked
increase in portions consumed by Americans, particularly in fast food and other restaurants is well
documented.Close contact with dieticians and other health professionals is essential for patients to learn how
to estimate portion sizes and calorie content, as well as methods to increase physical activity and to provide
support.The Diabetes Prevention Program, for example, provided subjects with 16 one-hour visits to help
them master the comprehensive program. 3Food models that illustrate portion sizes and use of prescribed
Diet Plate and Breakfast Bowl may also be helpful. 4 Recent studies have investigated the merits of diets
that are lower in total carbohydrate. These diets typically have higher proportions of fat and/or protein. The
Atkins Diet and the South Beach Diet are examples of diets that restrict carbohydrate.Dozens of clinical
studies have compared diets with different levels of carbohydrate for their effectiveness in weight loss.These
studies consistently show roughly equal amounts of weight loss between the two diet approaches.Despite the
higher proportion of fat in the low carbohydrate group, few significant differences in blood cholesterol,
blood sugar, or other important metabolic parameters are observed between the two diet types.Similar
results have been shown with comparisons of other popular diets including the Zone and the low-fat Ornish
program. The primary predictor of weight loss in these studies is adherence to the dietary program, not the
type of diet. 5, 6
Another important approach to weight loss diets is the use of meal replacements.These are low calorie diets
in which all or most food is provided by the weight loss plan.These can be as pre-packaged meals or as
combinations of bars, shakes, and soups.Meal replacement programs assist some patients by eliminating
many of the decisions related to food planning, food preparation, and portion control.In this manner, it may
easier to achieve calorie restriction for some individuals. Although most meal replacement programs also
aim for a 500-calorie per day energy deficit, greater restriction can be achieved.When such diets provide less
than 800 calories per day they are known as very-low calorie diets (VLCDs).VLCDs have been shown to
result in greater initial weight loss, closer to two pounds per week, than typical low calorie diets (LCDs). On
average such programs result in 15% of initial weight lost at one year, again with a wide variation among
individuals. Comparison between 400, 600, and 800 calories per day has demonstrated that 800 per day is
safer and equally effective.
The long-term effectiveness of VLCDs, compared to LCDs, is variable. Although some studies show
improved long-term maintenance of weight loss, most studies suggest that the two approaches are equivalent
over years of follow-up.
Nonetheless, the more rapid pace of weight loss that can be achieved with VLCDs makes them very useful
in clinical circumstances in which rapid weight loss is particularly useful.Examples include weight loss prior
to surgery including orthopedic surgery, transplant surgery and bariatric surgery), very poorly controlled
diabetes mellitus type 2, and other obesity-related disabling conditions. VLCDs should be used in
comprehensive programs that offer close medical supervision as well as interprofessional services to assist
with increases in physical activity, behavioral therapy, and social support.Patients who successfully lose
large amounts of weight rapidly may have important unexpected psychological concerns that need to be
addressed.Special attention must also be placed on the transition back to normal diets to prevent weight
regain.
Dr. Baron's Clinical Pearls:Weight loss diets and programs can work, but they require a substantial
commitment of effort.Almost any diet plan can work.Adherence to the diet is the primary predictor of
success.For individuals who have difficulty with portion control and counting calories, a healthy low
carbohydrate approach, like the South Beach Diet, may be effective.Meal replacement programs may also be
an effective alternative.In highly motivated patients with moderate and severe obesity (BMIs greater than 35
kg/m2), VLCDs can also be an effective alternative. Select a program with comprehensive services and a
long track record of success. Because transition from meal replacement back to a regular diet is so difficult,
my approach is to teach principles of weight maintenance (see below) over one month prior to beginning the
VLCD. Almost all patients that I have cared for who have lost more than 50 pounds and kept it off without
surgery, have done so with a VLCD.
Weight MaintenanceAlthough many dietary approaches can help lose weight, weight loss is only useful in
the long term if it can be kept off.Numerous studies have tried to describe the behaviors that are most
predictive of weight maintenance.The most important is the National Weight Control Registry (NWCR) at
www.nwcr.ws.
The NWCR was established in 1994 to examine the behaviors of successful weight losers. To enter the
registry, one most have lost at least 30 pounds and kept it off for one year. In fact the 5,000 registrants have
lost over 65 pounds and kept it off for over five years.The average starting BMI was 36.7 kg/m2 and the
current BMI is 25.1 kg/m2.
Several key factors define this group of successful weight losers. First, NWCR members continue to eat a
low calorie diet, typically less than 1400 calories per day. On average, fat intake is low, equaling less than
30% of calories. Interestingly though, those patients who restrict carbohydrate have also been successful in
maintaining their weight loss.Second, members engage in very high levels of physical activity totaling
almost 2700 calories per week.This is equivalent to moderate exercise, such as a brisk walk, for one hour per
day, six days per week.Third, they monitor their weight regularly.Over two-thirds weigh themselves daily or
weekly.NWCR members also limit television viewing, maintain dietary consistency on the weekends, eat
breakfast regularly, and rarely eat fast food.
Dr. Baron's Clinical Pearls:Maintaining weight loss can be achieved but it is very hard work. It requires a
lifelong commitment to a surprisingly low calorie diet (1400 calories per day), an hour of exercise per day,
and a long list of behavioral strategies to reinforce weight maintenance. Individuals who desire weight loss
and want to keep it off should understand the need to build these skills early in the weight loss process.
There is little point trying to lose weight without a commitment to weight maintenance.
Exercise for Weight Loss and Weight Maintenance
Aerobic exercise has a complex, important relationship to weight loss and weight maintenance. Aerobic
exercise without concurrent dietary changes has a very modest role in weight loss.Similarly, exercise plus
dietary changes compared to diet alone leads to very modest increases in weight loss, approximately one
extra kilogram. The effect, however, is increased by both increased intensity of exercise and increased
duration.
Despite the absence of large amounts of weight loss with exercise, metabolic factors consistently improve.
Elevations in blood pressure, blood lipids (especially blood triglycerides, HDL-cholesterol) and blood sugar
all improve with exercise. Here, too, the effect is increased with greater intensity and duration of exercise.
As discussed above, the NWCR suggests that even though exercise is not an essential factor for weight loss,
it is one of the key predictors of successful weight maintenance.
Most importantly, regular aerobic exercise is associated with striking improvements in obesity-related
illness and premature death.One large study, for example, studied individuals with different body weights
and different amounts of fitness (as measured by formal exercise testing). 8Individuals who were obese and
not fit had a three-fold increase risk of death after 14 years of follow-up as compared to individuals who
were normal weight and fit.Most interestingly, individuals who were obese but fit had an indistinguishable
death rate from the normal weight and fit group. This study, and several others done more recently, suggest
that fitness can decrease the risk of the negative health effects of obesity.
Dr. Baron's Clinical Pearls:Most individuals with mild to moderate obesity can start a regular exercise
program without medical supervision.Identify the amount of exercise that one can do comfortably and start
doing it regularly. Current recommendations are to exercise 6 days per week, building up to 60 minutes per
day of moderate intensity exercise (or 30-45 minutes of more intense exercise).Initially, focus on regularity
and duration, rather than intensity. For most individuals early morning exercise is best, but any time of day
will work.Plan your exercise in advance, and keep track of your performance.Identify a second -back-up-
exercise to reduce the risk of overuse injuries.Several studies have suggested that having an exercise
machine in the home can facilitate these principles.Pedometers have also been shown to increase physical
activity, particularly in those who set a goal of 10,000 steps per day.9 Resistance training and flexibility are
also important aspects of fitness for both the thin and the obese.
Behavior Therapy and Social Support
Successful weight loss, weight maintenance, and increased physical activity require sustained changes in
behavior.Behavior therapy has been shown to be a useful tool in changing both eating and exercise
behaviors.Behavior therapy can be implemented individually or in groups. Psychologists, dieticians or other
health professionals typically lead formal programs. Many skills can also be learned less formally.
Controlled studies demonstrate a significant increase in weight loss with behavioral therapy compared to
controls.
Behavior therapy relies on specific strategies to change problematic behaviors. Weekly goal setting creates a
sense of self-efficacy and can be useful in reinforcing further change. Self-monitoring includes tracking food
and beverage intake and physical activity.Recording the setting and emotional state associated with the
behavior may allow specific factors to become targets for change. Stimulus control requires identification of
both food and non-food cues that increase both desired and unwanted behaviors. Simple strategies such as
keeping certain foods out of the home may be helpful.Cognitive restructuring such as identifying obstacles
to success and identifying specific solutions may be helpful for some individuals.Dysfunctional thoughts
that interfere with goals are replaced with more rational thoughts. Formal cognitive behavioral therapy with
a trained psychologist can facilitate these processes.
Social support is also an important part of most successful weight management programs. Peer support, diet
partnerships, family involvement, and close contact with weight loss professionals have all been shown to be
effective.
Dr. Baron's Clinical Pearls:Plan today what you will eat tomorrow and when you will exercise
tomorrow.Involve family and friends and consider joining a formal support group or individual counseling.
Medications for Obesity
Numerous medications are widely available for weight loss. Medications, including both FDA-approved and
non-approved medications, can be obtained over-the counter, on the Internet, and by physician prescription.
Numerous randomized clinical trials have compared medications to placebos for the treatment of weight
loss.Overall, medications result in 3-5% more weight loss (from initial body weight) than placebos.10Most
of these studies have been limited to patients already following well-structured lifestyle modification
programs. Weight loss in less highly selected patients is likely to be lower.Few studies have directly
compared multiple medications, but on average there does not appear to be a significant advantage of one
drug over another.
Prescription medications for weight loss in the United States include highly restricted (Drug Enforcement
Administration schedule II and III) medications such as various amphetamines, benzphetamine, and
phendimetrazine. Most obesity experts agree that there is no role for such medications in treatment of
obesity.More commonly used medications include phentermine, diethylproprion, mazindol, sibutramine and
orlistat.Only the latter two are approved by the FDA for longer-term use (one or two years).Orlistat, at half
the prescription dose, is also available over-the-counter in the United States.
Regular use of weight loss medications, combined with lifestyle changes, results in modest amounts of
weight loss (3-5% of initial body weight) and modest improvements in obesity-related metabolic
factors.Longer studies, however, demonstrate that weight is typically regained after discontinuation of the
medication.This has led some experts to suggest that obesity medications should be continued long term,
analogous to treatment of other chronic conditions like hypertension, lipid disorders, and diabetes. To date,
however, there are no clinical studies that demonstrate that such an approach improves obesity-related health
outcomes and the FDA has not approved these medications for use in this manner.
Many other classes of medications are under investigation for weight loss.Most notable has been
rimonabant, a cannabinoid receptor blocker.This medication, similar to other weight loss medications,
results in an average weight loss of 5% of initial weight.Unfortunately, the drug was associated with
increased reports of depression and suicidality.The medication was withdrawn from sales development in
the United States in June 2007.
Dr. Baron's Clinical Pearls:Despite National Institute of Health (NIH) guidelines that state that FDA-
approved medications may be used in patients with BMI over 30 kg/m2 (or over 27 kg/m2 with obesity-
associated illnesses), I rarely recommend medications.Weight loss is modest, side effects are common, and
the cost of medications is high.
If medications are to be used, they should be used in conjunction with a structured lifestyle modification
program.In fact, my preference is to assure adherence to such a program prior to initiating the medication.
Medications use should be re-evaluated monthly, especially early in treatment.Results at the end of the first
month are highly predictive of results at 12 months.Thus, individuals who have not lost significant weight in
the first month should be advised to discontinue the medication.
Surgery for Weight Loss
Multiple surgical procedures are now available to treat severe obesity. In fact, surgery for obesity is one of
the fastest growing operations in the world. Practice guidelines of the U.S. National Institutes of Health
define surgery as a treatment option for patients with a BMI greater than or equal to 40 kg/m2 and for
patients with BMI greater than or equal to 35 kg/m2 with co-morbid conditions.This makes well over 5% of
the U.S. population eligible for what is known as bariatric surgery.
Bariatric procedures are designed to produce weight loss by two basic methods. Restrictive procedures,
including gastric banding, gastroplasty, and most gastric bypass procedures, make the stomach smaller and
lead to feelings of fullness.Malabsorptive procedures interfere with nutrient absorption; they include
biliopancreatic diversion, duodenal switch, jejunoileal bypass, and long limb gastric bypass.Many centers in
the U.S. have avoided malabsorptive procedures, despite excellent weight loss and patient acceptance, due
to questions of long-term safety. The most common procedure in the United States, the roux-en-y gastric
bypass, is typically performed to create both a restrictive and a modest malabsorptive component.Most
procedures in the U.S. are now performed laparoscopically (minimally invasive) and some can be done as
outpatient surgery.
On average, bariatric surgery leads to substantially more weight loss than any other weight loss method.The
Swedish Obese Subjects Study, for example, followed 4047 patients for almost 11 years after surgery.
11Gastric bypass patients had a maximum weight loss of 32% of their initial weight and 25% weight loss at
the end of the study.Vertical banded gastroplasty patients lost a maximum of 25%, with 16% at the end of
11 years. Laparoscopic banding led to 20% maximum and 14% at the study's conclusion.
Weight loss surgery also leads to a marked reduction in obesity-related morbidity.Substantial reductions are
seen in diabetes control, lipid management, hypertension control, sleep apnea, and a variety of other clinical
conditions.12Results are proportional to weight loss. Procedures that lead to greater weight loss have more
likelihood of leading to a complete resolution of each co-morbid condition.
Weight loss surgery, however, can also result in post-operative complications and death. Laparoscopic
banding, for example, can result in prolapse (falling out of place) of the stomach through the band,
infections of the reservoir, severe esophagitis, gastroesophageal reflux disease, and the need for conversion
to a roux-en-y bypass.Similarly gastric bypass procedures can result in bleeding, leaks, and infections.
Vitamin and mineral deficiencies can occur, including deficiencies of fat-soluble vitamins A, D, E and K,
vitamin B12, and minerals such as iron and calcium.
A meta-analysis of 136 published studies including 22,092 patients demonstrated an operative mortality
(death rate) of 0.1% for gastric banding and gastroplasty, 0.5% for gastric bypass, and 1.1% for
biliopancreatic diversion or duodenal switch.12 Data from community-based studies, however, suggest a
higher mortality rate.13Rates increase with age and with associated co-morbidities. In individuals between
the age of 55 and 64 covered by Medicare, for example, the 30-day mortality rate is closer to 2%.As a result,
more surgeries in the United States are performed in women with private insurance who live in wealthier zip
codes.Such patients are likely at lower risk of complications, but also may receive less long term benefit of
surgery.
The Swedish Obese Subjects Study has recently reported on overall long-term survival from obesity surgery.
14Patients with surgery had a 24% reduction in death over 11 years compared to control patients. The
absolute death rate, however, was low in both groups.Approximately 850 patients need to have weight loss
surgery to prevent one death per year.
Dr. Baron's Clinical Pearls:Major advances in weight loss surgery have occurred in the last decade.The
procedure is now widely and safely performed, is covered by most insurance payers, and is both effective
and cost-effective.The short-term risk of complications, including per-operative mortality, is significant,
however, and may be underestimated in higher risk patients.Longer-term complications are also more
common than appreciated and not all patients have ideal outcomes.Deciding to have surgery is thus a very
difficult decision for both patients and clinicians.I recommend surgery to patients at high risk of obesity-
related conditions who fully understand the risk of surgical complications.Patients must be in good
psychological health, adherent to medical recommendations, and be committed to a lifetime of lifestyle
changes post-operatively.Requiring patients prior to surgery to lose approximately 5-10% of their body
weight with diet, exercise and behavioral therapy, is a useful test of both the patient's commitment to change
and their skills in long-term weight management.Most importantly, patients should seek weight loss surgery
at major centers who perform high volumes of operations and who can provide multidisciplinary care pre-
and post-operatively.
Prevention of Obesity
Obesity and decreased physical activity are having a devastating impact on public health in the United States
and much of the world.Obesity is second only to cigarette use in causing preventable deaths.Weight loss
without surgery is difficult to achieve and maintain, and with surgery is expensive, complicated, and
associated with its own risk.
Individuals can implement specific behavioral strategies to prevent weight gain. In general, such strategies
are identical to those discussed above for weight loss and weight maintenance.Basic principles such as
consuming low calorie diets, performing high levels of physical activity most days of the week, and regular
monitoring of weight are essential.Limiting portion sizes, avoiding excess calories in beverages (both
alcoholic and non-alcoholic), eating breakfast, avoiding fast food, and regular meal planning and record
keeping are all useful tools.In the United States, since weight gain with aging is the norm, most individuals
will need a conscious weight maintenance strategy to prevent further weight gain.
Social policy changes, analogous to policies implemented to decrease tobacco use, are also necessary to
have a substantial impact on obesity. 15
Some may perceive many of these as draconian, but there is little evidence that anything but dramatic social
changes will be effective.Proposals include selective taxes and subsidies for food grown, marketed and
consumed; regulations on food advertisements; increased social marketing; enhanced labeling of caloric
content of foods in markets and restaurants; changes in school lunch, food stamp, and beverage programs;
more opportunities for physical activity at work, school and in the community; and a greater emphasis and
investment in public transportation.
References and further reading
1.Flegal KM, Graubard BI, Williamson DF, Gail MH. Cause-Specific Excess Deaths Associated With
Underweight, Overweight, and Obesity. JAMA. 2007;298(17):2028-2037.
2.Tsai AG, Wadden TA. Systematic review:an evaluation of major commercial weight loss programs in the
United States. Ann Intern Med. 2005; Jan 4;142(1):56-66.
3.Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, Nathan DM; Diabetes
Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle
intervention or metformin. N Engl J Med. 2002; Feb 7;346(6):393-403.
4.Pedersen SD, Kang J, Kline GA. Portion control plate for weight loss in obese patients with type 2
diabetes mellitus: a controlled clinical trial.Arch Intern Med. 2007; Jun 25;167(12):1277-83.
5.Dansinger ML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ.Comparison of the Atkins, Ornish,
Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial.
JAMA. 2005; Jan 5;293(1):43-53.
6.Gardner CD, 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; Mar 7;297(9):969-77.
7.Gilden Tsai A, . The evolution of very-low-calorie diets: an update and meta-analysis. Obesity (Silver
Spring). 2006 Aug;14(8):1283-93.
8. Wei M, Kampert JB, Barlow CE, Nichaman MZ, Gibbons LW, Paffenbarger RS Jr, Blair SN.
Relationship between low cardiorespiratory fitness and mortality in normal-weight, overweight, and obese
men. JAMA. 1999 Oct 27;282(16):1547-53.
9.Bravata DM, Smith-Spangler C, Sundaram V, et al. Using Pedometers to Increase Physical Activity and
Improve Health: A Systematic Review. JAMA. 2007;298(19):2296-2304.
10. Glazer G.Long-term pharmacotherapy of obesity 2000: a review of efficacy and safety. Arch Intern
Med. 2001 Aug 13-27;161(15):1814-24.
11. Sjstrm L, Narbro K, Sjstrm CD, et al. Effects of Bariatric Surgery on Mortality in Swedish Obese
Subjects. NEngl J Med. 2007 Aug 23:357(8): 741-752.
12.Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, SchoellesK. Bariatric surgery:
a systematic review and meta-analysis.JAMA 2004; 292 (14):1724-37.
13. Flum DR, Salem L, Elrod JA, Dellinger EP, Cheadle A, Chan L. Early mortality among Medicare
beneficiaries undergoing bariatric surgical procedures. JAMA. 2005 Oct 19;294(15):1903-8.
14.Sjstrm L, Narbro K, Sjstrm CD, Karason K, Larsson B, Wedel H, Lystig T,Sullivan M, Bouchard C,
Carlsson B, Bengtsson C, Dahlgren S, Gummesson A, Jacobson P, Karlsson J, Lindroos AK, Lnroth H,
Nslund I, Olbers T, Stenlf K, Torgerson J, Agren G, Carlsson LM; Swedish Obese Subjects Study. Effects
of bariatric surgery on mortality in Swedish obese subjects. N Engl J Med. 2007 Aug 23;357(8):741-52.
15.Schroeder, SA Shattuck Lecture. We can do better--improving the health of the American people. N Engl
J Med. 2007 Sep 20;357(12):1221-8.
loss weight from docstoc