Weight (Body Mass)

 Your weight is the mass or quantity of your heaviness. It is expressed by units of pounds or kilograms.

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Do you know if your current weight is healthy? "Underweight", "normal", "overweight", and "obese" are all labels for ranges of weight. Obese and overweight mean that your weight is greater than it should be for your health. Underweight means that it is lower than it should be for your health. Your healthy body weight depends on your sex and height. For children, it also depends on your age.

A sudden, unexpected change in weight can be a sign of a medical problem. Causes for sudden weight loss can include

• Thyroid problems
• Cancer
• Infectious diseases
• Digestive diseases
• Certain medicines

Sudden weight gain can be due to medicines, thyroid problems, heart failure, and kidney disease.

Good nutrition and exercise can help in losing weight. Eating extra calories within a well-balanced diet and treating any underlying medical problems can help to add weight.

Reaching and maintaining a healthy weight is important for overall health and can help you prevent and control many diseases and conditions. If you are overweight or obese, you are at higher risk of developing serious health problems, including heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers. That is why maintaining a healthy weight is so important: It helps you lower your risk for developing these problems, helps you feel good about yourself, and gives you more energy to enjoy life. 

What Is Overweight and Obesity?

Overweight is having extra body weight from muscle, bone, fat, and/or water. Obesity is having a high amount of extra body fat. Body mass index (BMI) is a useful measure of overweight and obesity. The information on this Web site will provide you with information about BMI (including limitations of this measure) and how to reach and stay at a healthy weight. Talk to your health care provider if you are concerned about your BMI.

What Factors Contribute To a Healthy Weight?

Many factors can contribute to a person’s weight. These factors include environment, family history and genetics, metabolism (the way your body changes food and oxygen into energy), and behavior or habits.

Energy Balance

Energy balance is important for maintaining a healthy weight. The amount of energy or calories you get from food and drinks (energy IN) is balanced with the energy your body uses for things like breathing, digesting, and being physically active (energy OUT):

• The same amount of energy IN and energy OUT over time = weight stays the same (energy balance)
• More energy IN than OUT over time = weight gain
• More energy OUT than IN over time = weight loss

To maintain a healthy weight, your energy IN and OUT don’t have to balance exactly every day. It’s the balance over time that helps you maintain a healthy weight.

You can reach and maintain a healthy weight if you:

• Follow a healthy diet, and if you are overweight or obese, reduce your daily intake by 500 calories for weight loss
• Are physically active
• Limit the time you spend being physically inactive

Body mass index (BMI) is a person’s weight in kilograms divided by the square of height in meters. BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity.

BMI does not measure body fat directly, but BMI is moderately correlated with more direct measures of body fat. Furthermore, BMI appears to be as strongly correlated with various metabolic and disease outcome as are these more direct measures of body fatness

How is BMI used?

BMI can be a screening tool, but it does not diagnose the body fatness or health of an individual. To determine if BMI is a health risk, a healthcare provider performs further assessments. Such assessments include skinfold thickness measurements, evaluations of diet, physical activity, and family history.

What are the BMI trends for adults in the United States?

The prevalence of adult BMI greater than or equal to 30 kg/m² (obese status) has greatly increased since the 1970s. Recently, however, this trend has leveled off, except for older women. Obesity has continued to increase in adult women who are age 60 years and older.

Why is BMI used to measure overweight and obesity?

Because calculation requires only height and weight, BMI is an inexpensive and easy tool.

What are some of the other ways to assess excess body fatness besides BMI?

Other methods to measure body fatness include skinfold thickness measurements (with calipers), underwater weighing, bioelectrical impedance, dual-energy x-ray absorptiometry (DXA), and isotope dilution. However, these methods are not always readily available, and they are either expensive or need to be conducted by highly trained personnel. Furthermore, many of these methods can be difficult to standardize across observers or machines, complicating comparisons across studies and time periods.

How is BMI calculated?

BMI is calculated the same way for both adults and children. The calculation is based on the following formulas:

How is BMI interpreted for adults?

For adults 20 years old and older, BMI is interpreted using standard weight status categories. These categories are the same for men and women of all body types and ages.

For example, here are the weight ranges, the corresponding BMI ranges, and the weight status categories for a person who is 5′ 9″.

For children and teens, the interpretation of BMI depends upon age and sex.

Is BMI interpreted the same way for children and teens as it is for adults?

BMI is interpreted differently for children and teens, even though it is calculated using the same formula as adult BMI. Children and teen’s BMI need to be age and sex-specific because the amount of body fat changes with age and the amount of body fat differs between girls and boys. The CDC BMI-for-age growth charts take into account these differences and visually show BMI as a percentile ranking. These percentiles were determined using representative data of the U.S. population of 2- to 19-year-olds that was collected in various surveys from 1963-65 to 1988-94.

Obesity among 2- to 19-year-olds is defined as a BMI at or above the 95^th percentile of children of the same age and sex in this 1963 to 1994 reference population. For example, a 10-year-old boy of average height (56 inches) who weighs 102 pounds would have a BMI of 22.9 kg/m². This would place the boy in the 95^th percentile for BMI – meaning that his BMI is greater than that of 95% of similarly aged boys in this reference population – and he would be considered to have obesity.

How good is BMI as an indicator of body fatness?

The correlation between the BMI and body fatness is fairly strong, but even if 2 people have the same BMI, their level of body fatness may differ.

In general,

• At the same BMI, women tend to have more body fat than men.
• At the same BMI, the amount of body fat may be higher or lower depending on the racial/ethnic group.
• At the same BMI, older people, on average, tend to have more body fat than younger adults.
• At the same BMI, athletes have less body fat than do non-athletes.

The accuracy of BMI as an indicator of body fatness also appears to be higher in persons with higher levels of BMI and body fatness. While, a person with a very high BMI (e.g., 35 kg/m²) is very likely to have high body fat, a relatively high BMI can be the results of either high body fat or high lean body mass (muscle and bone). A trained healthcare provider should perform appropriate health assessments in order to evaluate an individual’s health status and risks.

If an athlete or other person with a lot of muscle has a BMI over 25, is that person still considered to be overweight?

According to the BMI weight status categories, anyone with a BMI between 25 and 29.9 would be classified as overweight and anyone with a BMI over 30 would be classified as obese.

However, athletes may have a high BMI because of increased muscularity rather than increased body fatness. In general, a person who has a high BMI is likely to have body fatness and would be considered to be overweight or obese, but this may not apply to athletes. A trained healthcare provider should perform appropriate health assessments in order to evaluate an individual’s health status and risks.

What are the health consequences of obesity for adults?

People who have obesity are at increased risk for many diseases and health conditions, including the following:

• All-causes of death (mortality)
• High blood pressure (hypertension)
• High LDL cholesterol, low HDL cholesterol, or high levels of triglycerides (dyslipidemia)
• Type 2 diabetes
• Coronary heart disease
• Stroke
• Gallbladder disease
• Osteoarthritis (a breakdown of cartilage and bone within a joint)
• Sleep apnea and breathing problems
• Chronic inflammation and increased oxidative stress
• Some cancers (endometrial, breast, colon, kidney, gallbladder, and liver)
• Low quality of life
• Mental illness such as clinical depression, anxiety, and other mental disorders
• Body pain and difficulty with physical functioning

Assessment of weight and health risk involves using three key measures:

1. Body mass index (BMI)
2. Waist circumference
3. Risk factors for diseases and conditions associated with obesity

Body Mass Index (BMI)

BMI is a useful measure of overweight and obesity. It is calculated from your height and weight. BMI is an estimate of body fat and a good gauge of your risk for diseases that can occur with more body fat. The higher your BMI, the higher your risk for certain diseases such as heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers.

Waist Circumference

Measuring waist circumference helps screen for possible health risks that come with overweight and obesity. If most of your fat is around your waist rather than at your hips, you’re at a higher risk for heart disease and type 2 diabetes. This risk goes up with a waist size that is greater than 35 inches for women or greater than 40 inches for men. To correctly measure your waist, stand and place a tape measure around your middle, just above your hipbones. Measure your waist just after you breathe out.

Risk Factors Associated With Obesity

Along with being overweight or obese, the following conditions will put you at greater risk for heart disease and other conditions:

• High blood pressure (hypertension)
• High LDL cholesterol ("bad" cholesterol)
• Low HDL cholesterol ("good" cholesterol)
• High triglycerides
• High blood glucose (sugar)
• Family history of premature heart disease
• Physical inactivity
• Cigarette smoking

For people who are considered obese (BMI greater than or equal to 30) or those who are overweight (BMI of 25 to 29.9) and have two or more risk factors, it is recommended that you lose weight. Even a small weight loss (between 5 and 10 percent of your current weight) will help lower your risk of developing diseases associated with obesity. People who are overweight, do not have a high waist measurement, and have fewer than two risk factors may need to prevent further weight gain rather than lose weight.

Talk to your doctor to see whether you are at an increased risk and whether you should lose weight. Your doctor will evaluate your BMI, waist measurement, and other risk factors for heart disease.

The good news is even a small weight loss (between 5 and 10 percent of your current weight) will help lower your risk of developing those diseases.

Overweight and obesity may raise your risk for certain health problems and may be linked to certain emotional and social problems.

What are some health risks of overweight and obesity?

Type 2 diabetes

Type 2 diabetes is a disease that occurs when your blood glucose, also called blood sugar, is too high. About 8 out of 10 people with type 2 diabetes are overweight or have obesity.⁸ Over time, high blood glucose leads to problems such as heart disease, stroke, kidney disease, eye problems, nerve damage, and other health problems.

If you are at risk for type 2 diabetes, losing 5 to 7 percent of your body weight and getting regular physical activity may prevent or delay the onset of type 2 diabetes.

High blood pressure

High blood pressure, also called hypertension, is a condition in which blood flows through your blood vessels with a force greater than normal. High blood pressure can strain your heart, damage blood vessels, and raise your risk of heart attack, stroke, kidney disease, and death.

Heart disease

Heart disease is a term used to describe several problems that may affect your heart. If you have heart disease, you may have a heart attack, heart failure, sudden cardiac death, angina, or an abnormal heart rhythm. High blood pressure, abnormal levels of blood fats, and high blood glucose levels may raise your risk for heart disease. Blood fats, also called blood lipids, include HDL cholesterol, LDL cholesterol, and triglycerides.

Losing 5 to 10 percent of your weight may lower your risk factors for developing heart disease. If you weigh 200 pounds, this means losing as little as 10 pounds. Weight loss may improve blood pressure, cholesterol levels, and blood flow.

Stroke

Stroke is a condition in which the blood supply to your brain is suddenly cut off, caused by a blockage or the bursting of a blood vessel in your brain or neck. A stroke can damage brain tissue and make you unable to speak or move parts of your body. High blood pressure is the leading cause of strokes.

Sleep apnea

Sleep apnea is a common disorder in which you do not breathe regularly while sleeping. You may stop breathing altogether for short periods of time. Untreated sleep apnea may raise your risk of other health problems, such as type 2 diabetes and heart disease.

Metabolic syndrome

Metabolic syndrome is a group of conditions that put you at risk for heart disease, diabetes, and stroke. These conditions are

• high blood pressure
• high blood glucose levels
• high triglyceride levels in your blood
• low levels of HDL cholesterol (the “good” cholesterol) in your blood
• too much fat around your waist

Fatty liver diseases

Fatty liver diseases are conditions in which fat builds up in your liver. Fatty liver diseases include nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Fatty liver diseases may lead to severe liver damage, cirrhosis, or even liver failure.

Osteoarthritis

Osteoarthritis is a common, long-lasting health problem that causes pain, swelling, and reduced motion in your joints. Being overweight or having obesity may raise your risk of getting osteoarthritis by putting extra pressure on your joints and cartilage.

Gallbladder diseases

Overweight and obesity may raise your risk of getting gallbladder diseases, such as gallstones and cholecystitis. Imbalances in substances that make up bile cause gallstones. Gallstones may form if bile contains too much cholesterol.

Some cancers

Cancer is a collection of related diseases. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues. Overweight and obesity may raise your risk of developing certain types of cancer.

Kidney disease

Kidney disease means that your kidneys are damaged and can’t filter blood like they should. Obesity raises the risk of diabetes and high blood pressure, the most common causes of kidney disease. Even if you don’t have diabetes or high blood pressure, obesity itself may promote kidney disease and quicken its progress.

Pregnancy problems

Overweight and obesity raise the risk of health problems that may occur during pregnancy. Pregnant women who are overweight or obese may have a greater chance of

• developing gestational diabetes
• having preeclampsia—high blood pressure during pregnancy, which can cause severe health problems for mother and baby if left untreated
• needing a cesarean section, or C-section and, as a result, taking longer to recover after giving birth

What emotional and social problems are linked to overweight and obesity?

Overweight and obesity are associated with mental health problems such as depression. People who deal with overweight and obesity may also be the subject of weight bias and stigma from others, including health care providers. This can lead to feelings of rejection, shame, or guilt—further worsening mental health problems.

Your Weight Is Important

Over the past few years it has become clear that weight is an important health issue. Some people who need to lose weight for their health don't recognize it, while others who don't need to lose weight want to get thinner for cosmetic reasons. We understand that in some ways your weight is different from, for example, your cholesterol level or your blood pressure, because you can't see what these are by looking at someone. Many patients have had health care providers who approached their weight in a less-than-sensitive or helpful manner. Some patients may have had health care encounters in which they felt blamed, but not helped. Successful weight management is a long-term challenge.

Weight can affect a person's self-esteem. Excess weight is highly visible and evokes some powerful reactions, however unfairly, from other people and from the people who carry the excess weight. The amount of weight loss needed to improve your health may be much less than you wish to lose, when you consider how you evaluate your weight. Research has shown that your health can be greatly improved by a loss of 5–10 percent of your starting weight. That doesn't mean you have to stop there, but it does mean that an initial goal of losing 5–10 percent of your starting weight is both realistic and valuable.

Behaviors That Will Help You Lose Weight and Maintain It

Set the Right Goals
Setting the right goals is an important first step. Most people trying to lose weight focus on just that one goal: weight loss. However, the most productive areas to focus on are the dietary and physical activity changes that will lead to long-term weight change. Successful weight managers are those who select two or three goals at a time that are manageable.

Useful goals should be (1) specific; (2) attainable (doable); and (3) forgiving (less than perfect). "Exercise more" is a great goal, but it's not specific. "Walk 5 miles every day" is specific and measurable, but is it doable if you're just starting out? "Walk 30 minutes every day" is more attainable, but what happens if you're held up at work one day and there's a thunderstorm during your walking time another day? "Walk 30 minutes, 5 days each week" is specific, doable, and forgiving. In short, a great goal!

Nothing Succeeds Like Success

Shaping is a behavioral technique in which you select a series of short-term goals that get closer and closer to the ultimate goal (e.g., an initial reduction of fat intake from 40 percent of calories to 35 percent of calories, and later to 30 percent). It is based on the concept that "nothing succeeds like success." Shaping uses two important behavioral principles: (1) consecutive goals that move you ahead in small steps are the best way to reach a distant point; and (2) consecutive rewards keep the overall effort invigorated.

Reward Success (But Not With Food)

An effective reward is something that is desirable, timely, and dependent on meeting your goal. The rewards you choose may be material (e.g., a movie or music CD, or a payment toward buying a more costly item) or an act of self-kindness (e.g., an afternoon off from work or just an hour of quiet time away from family). Frequent small rewards, earned for meeting smaller goals, are more effective than bigger rewards that require a long, difficult effort.

Balance Your Food Checkbook

"Self-monitoring" refers to observing and recording some aspect of your behavior, such as calorie intake, servings of fruits and vegetables, amount of physical activity, etc., or an outcome of these behaviors, such as weight. Self-monitoring of a behavior can be used at times when you're not sure how you're doing, and at times when you want the behavior to improve. Self-monitoring of a behavior usually moves you closer to the desired direction and can produce "real-time" records for review by you and your health care provider. For example, keeping a record of your physical activity can let you and your provider know quickly how you're doing. When the record shows that your activity is increasing, you'll be encouraged to keep it up. Some patients find that specific self-monitoring forms make it easier, while others prefer to use their own recording system.

While you may or may not wish to weigh yourself frequently while losing weight, regular monitoring of your weight will be essential to help you maintain your lower weight. When keeping a record of your weight, a graph may be more informative than a list of your weights. When weighing yourself and keeping a weight graph or table, however, remember that one day's diet and exercise patterns won't have a measurable effect on your weight the next day. Today's weight is not a true measure of how well you followed your program yesterday, because your body's water weight will change from day to day, and water changes are often the result of things that have nothing to do with your weight-management efforts.

Avoid a Chain Reaction

Stimulus (cue) control involves learning what social or environmental cues seem to encourage undesired eating, and then changing those cues. For example, you may learn from reflection or from self-monitoring records that you're more likely to overeat while watching television, or whenever treats are on display by the office coffee pot, or when around a certain friend. You might then try to change the situation, such as by separating the association of eating from the cue (don't eat while watching television), avoiding or eliminating the cue (leave the coffee room immediately after pouring coffee), or changing the circumstances surrounding the cue (plan to meet your friend in a nonfood setting). In general, visible and reachable food items are often cues for unplanned eating.

Get the Fullness Message

Changing the way you go about eating can make it easier to eat less without feeling deprived. It takes 15 or more minutes for your brain to get the message that you've been fed. Eating slowly will help you feel satisfied. Eating lots of vegetables and fruits can make you feel fuller. Another trick is to use smaller plates so that moderate portions do not appear too small. Changing your eating schedule, or setting one, can be helpful, especially if you tend to skip, or delay, meals and overeat later.

If you’re currently at a healthy weight, you’re already one step ahead of the game. To stay at a healthy weight, it’s worth doing a little planning now.

Or maybe you are overweight but aren’t ready to lose weight yet. If this is the case, preventing further weight gain is a worthy goal.

As people age, their body composition gradually shifts — the proportion of muscle decreases and the proportion of fat increases. This shift slows their metabolism, making it easier to gain weight. In addition, some people become less physically active as they get older, increasing the risk of weight gain.

The good news is that weight gain can be prevented by choosing a lifestyle that includes good eating habits and daily physical activity. By avoiding weight gain, you avoid higher risks of many chronic diseases, such as heart disease, stroke, type 2 diabetes, high blood pressure, osteoarthritis, and some forms of cancer.

Choosing an Eating Plan to Prevent Weight Gain

So, how do you choose a healthful eating plan that will enable you to maintain your current weight? The goal is to make a habit out of choosing foods that are nutritious and healthful. 

If your goal is to prevent weight gain, choose foods that supply the appropriate number of calories to maintain your weight. This number varies from person to person. It depends on many factors, including your height, weight, age, sex, and activity level. 

Get Moving!

In addition to a healthy eating plan, an active lifestyle will help you maintain your weight. Regular physical activity can reduce your risk for many chronic diseases and help keep your body healthy and strong. This makes it more likely you’ll maintain your weight.

Although physical activity is an integral part of weight management, it’s also a vital part of health in general. Regular physical activity can reduce your risk for many chronic diseases and it can help keep your body healthy and strong.

Self-monitoring

You may also find it helpful to weigh yourself on a regular basis. If you see a few pounds creeping on, take the time to examine your lifestyle. With these strategies, you make it more likely that you’ll catch small weight gains more quickly.

Ask yourself—

• Has my activity level changed? Use a diary to track your physical activity.
• Am I eating more than usual? Keeping a food diary for a few days may make you more aware of your eating choices.

If you ask yourself these questions and find that you’ve decreased your activity level or made some poor food choices, make a commitment to yourself to get back on track. If you find that you’ve decreased your activity level or made some poor food choices, make a commitment to yourself to get back on track.

Why is physical activity important?

Regular physical activity provides immediate and long-term health benefits. Being physically active can improve your brain health, reduce the risk of disease, strengthen bones and muscles, and improve your ability to do everyday activities.

Physical activity also helps:

• Improve sleep quality.
• Reduce high blood pressure.
• Reduce risk for type 2 diabetes, heart attack, stroke, and several forms of cancer.
• Reduce arthritis pain and associated disability.
• Reduce risk for osteoporosis and falls.
• Reduce symptoms of depression and anxiety.

In addition, physical activity is important if you are trying to lose weight or maintain a healthy weight.

• When losing weight, more physical activity increases the number of calories your body uses for energy. Using calories through physical activity, combined with reducing the calories you eat, creates a calorie deficit that results in weight loss.
• Most weight loss occurs from decreasing caloric intake. However, evidence shows the only way to maintain weight loss is to be engaged in regular physical activity.
• Most importantly, physical activity reduces risks of cardiovascular disease and diabetes beyond that produced by weight reduction alone.

How much physical activity do I need?

To maintain your weight: Work your way up to 150 minutes of moderate-intensity aerobic activity each week. This could be brisk walking 30 minutes a day, 5 days a week. Or you could do 75 minutes of vigorous-intensity aerobic activity each week, such as swimming laps.

The exact amount of physical activity needed to maintain a healthy weight varies greatly from person to person. You may need more than the equivalent of 150 minutes of moderate-intensity activity a week to maintain your weight.

To lose weight and keep it off: You will need a high amount of physical activity unless you also adjust your diet to reduce the number of calories you eat and drink. Getting to and staying at a healthy weight requires both regular physical activity and a healthy eating plan.

What do moderate- and vigorous-intensity mean?

Moderate: While performing the physical activity, if your breathing and heart rate is noticeably faster but you can still carry on a conversation — it’s probably moderately intense. Examples include:

• Walking briskly (a 15-minute mile).
• Light yard work (raking/bagging leaves or using a lawn mower).
• Light snow shoveling.
• Actively playing with children.
• Biking at a casual pace.

Vigorous: If your heart rate is increased substantially and you are breathing too hard and fast to have a conversation, it’s probably vigorously intense. Examples include:

• Jogging/running.
• Swimming laps.
• Rollerblading/inline skating at a brisk pace.
• Cross-country skiing.
• Most competitive sports (football, basketball, or soccer).
• Jumping rope.

How many calories are used in typical activities?

The following table shows calories used in common physical activities at both moderate and vigorous levels.

A healthy eating plan gives your body the nutrients it needs every day while staying within your daily calorie goal for weight loss. A healthy eating plan also will lower your risk for heart disease and other health conditions.

A healthy eating plan:

• Emphasizes vegetables, fruits, whole grains, and fat-free or low-fat dairy products
• Includes lean meats, poultry, fish, beans, eggs, and nuts
• Limits saturated and trans fats, sodium, and added sugars
• Controls portion sizes

Calories

To lose weight, most people need to reduce the number of calories they get from food and beverages (energy IN) and increase their physical activity (energy OUT).

For a weight loss of 1–1 ½ pounds per week, daily intake should be reduced by 500 to 750 calories. In general:

• Eating plans that contain 1,200–1,500 calories each day will help most women lose weight safely.
• Eating plans that contain 1,500–1,800 calories each day are suitable for men and for women who weigh more or who exercise regularly.

Very low calorie diets of fewer than 800 calories per day should not be used unless you are being monitored by your doctor.

Overweight and obese adults who drink diet beverages take in more calories from solid foods—especially snacks—than those who drink sugary beverages, according to a new study. The findings raise questions about using diet drinks for weight control in heavier adults.

Excess weight can raise your risk for many health problems, including type 2 diabetes, cancer, and heart disease. Many people use diet drinks to help control their weight. But studies of how these beverages affect weight control have had mixed results.

To examine the link between diet drinks and calories, NIH-funded scientists looked at data on nearly 24,000 adults. The researchers found that about 10% of healthy-weight adults drank diet beverages, compared to about 20% of over-weight and obese adults.

Healthy-weight adults who drank diet beverages ate less food and fewer total calories on a typical day than those who drank sugared beverages.

Among adults who were over-weight or obese, total calorie intake was similar between those who drank diet or sugary beverages. Heavier adults who drank diet beverages tended to eat more calories in the form of solid foods.

Taking a look at solid-food intake, the scientists found that obese adults who consumed diet drinks ate significantly more calories per day in salty snacks and sweet snacks than those who drank sugared beverages.

“The results suggest that overweight and obese adults looking to lose or maintain their weight—who have already made the switch from sugary to diet beverages—may need to look carefully at other components of their solid-food diet,” says study coauthor Dr. Sara N. Bleich at the Johns Hopkins Bloomberg School of Public Health.

Future studies might test whether diet drinks help healthy-weight adults maintain their weight.

Check It Out: Before You Sign Up for Any Weight-Loss Program

Some people lose weight on their own; others like the support of a structured program. Overweight people who are successful at losing weight, and keeping it off, can reduce their risk factors for heart disease. If you decide to join any kind of weight-control program, here are some questions to ask before you join.

• Does the program provide counseling to help you change your eating activity and personal habits?
  The program should teach you how to change permanently those eating habits and lifestyle factors, such as lack of physical activity, that have contributed to weight gain.
• Is the staff made up of a variety of qualified counselors and health professionals such as nutritionists, registered dietitians, doctors, nurses, psychologists, and exercise physiologists?
  You need to be evaluated by a physician if you have any health problems, are currently taking any medicine or plan on taking any medicine, or plan to lose more than 15 to 20 pounds. If your weight-control plan uses a very low-calorie diet (a special liquid formula that replaces all food for 1 to 4 months), an exam and followup visits by a doctor also are needed.
• Is training available on how to deal with times when you may feel stressed and slip back to old habits?
  The program should provide long-term strategies to deal with weight problems you may have in the future. These strategies might include things like setting up a support system and establishing a physical activity routine.
• Is attention paid to keeping the weight off? How long is this phase?
  Choose a program that teaches skills and techniques to make permanent changes in eating habits and levels of physical activity to prevent weight gain.
• Are food choices flexible and suitable? Are weight goals set by the client and the health professional?
  The program should consider your food likes and dislikes and your lifestyle when your weight-loss goals are planned.

There are other questions you can ask about how well a weight-loss program works. Because many programs don't gather this information, you may not get answers. But it's still important to ask them:

• What percentage of people complete the program?
• What is the average weight loss among people who finish the program?
• What percentage of people have problems or side effects? What are they?
• Are there fees or costs for additional items, such as dietary supplements?

Remember, quick weight loss methods don't provide lasting results. Weight-loss methods that rely on diet aids like drinks, prepackaged foods, or diet pills don't work in the long run. Whether you lose weight on your own or with a group, remember that the most important changes are long term. No matter how much weight you have to lose, modest goals and a slow course will increase your chances of both losing the weight and keeping it off.

A study found that when people consumed a diet of highly processed foods, they took in more calories and gained more weight than when on a diet of minimally processed foods.

Researchers compared the effects of a highly processed and a minimally processed diet in 10 men and 10 women residing for four weeks at the NIH Clinical Center. Each diet lasted for two weeks. People received three meals per day plus snacks. They could eat as much or as little as they wanted.

Processed foods usually have a lot of calories, salt, sugar, and fat and are low in fiber, but the researchers matched the meals for these nutrients.

The highly processed diet had foods like canned ravioli, hot dogs, chicken nuggets, pork sausage, and tater tots. The minimally processed diet had foods like salad, grilled beef roast and vegetables, and baked fish. People noted that the diets both tasted good and were satisfying.

On the highly processed diet, people ate more calories and gained an average of 2 pounds. On the unprocessed diet, they ate fewer calories and lost about 2 pounds.

The results support the benefits of unprocessed foods. But the researchers note that processed foods can be difficult to avoid.

“Just telling people to eat healthier may not be effective for some people without improved access to healthy foods,” says NIH obesity expert Dr. Kevin Hall, who led the study.

More studies are needed to better understand how processed food affects weight.