Weight Loss Diet


Obesity is one of the most significant public health problems facing the United States. Excess weight is associated with increased risk for many diseases including diabetes, certain types of cancer, and cardiovascular disease.

Unfortunately, there is no magic bullet for weight loss, and many overweight people struggle for years to shed unwanted pounds. Researchers now believe that successful and permanent weight loss is only possible with comprehensive lifestyle changes that address eating behaviors, physical activity, and psychological factors such as goal-setting and self-esteem issues.

Losing weight is virtually impossible without cutting back on calories, but calorie restriction should not be so severe that you are hungry all of the time or that you are unable to attain sufficient amounts of essential nutrients.

The best approach is to moderately restrict calories and increase physical activity, so that you are able to burn more calories than you take in. A healthy weight-loss diet should include lots of fresh vegetables, fruits, whole grains, and beans. To help reduce caloric intake, cut back on sweetened beverages, and high-fat, high-calorie desserts and snack foods.


More than half of American adults are currently overweight, a number that has climbed steadily since the early 1960s. Since the late 1980's, the number of overweight children in the United States has more than doubled, so that now at least 11% of American children are overweight.

Throughout the 20th Century and into the 21st Century, a countless number of fad diets for weight loss, from the Cabbage Soup Diet to the Atkins Diet, have captured the attention of the American public. Unfortunately, most of these diets produce similar results — quick, but temporary weight loss.


As the United States population gets fatter and fatter, the American obsession with weight loss becomes more firmly entrenched in our society. Each year, more than one-half of all Americans start a weight reduction diet and nearly 50 million Americans are on a diet at any given time.

All this adds up to more than $30 billion spent each year trying to shed unwanted pounds - a number 1.5 times the gross domestic product of an entire country like Afghanistan.


In theory, the secret to weight loss is simple — eat fewer calories than your body burns to fuel normal physiological functions and physical activity. Your body expends a great deal of calories just to maintain your body temperature, to fuel functions essential to life such as circulation and respiration, and to fuel muscle movements during exercise.

When the amount of calories we eat is equal to the amount of calories we burn, our weight is stable. On the other hand, when we eat more calories than we burn, the extra calories are stored as fat and we begin to gain weight. One pound of stored fat is equivalent to 3,500 stored calories, which means that if you eat 500 more calories than you need each day for a week, you will gain one pound of body weight.

So, how can you get rid of those unwanted pounds? Most of the people who are able to lose weight and keep it off, use a two-pronged approach. This approach involves cutting back on calories slightly and increasing physical exercise.

Let's say your goal is to lose one pound per week. Remember that one pound of stored fat contains 3,500 calories. If you do nothing but cut calories, you will have to eat 500 fewer calories per day to lose one pound a week. For many people, cutting calories this severely is worse than torture, as they feel hungry all of the time and are tempted to cheat.

But, if you increase your physical activity and by doing so burn an extra 250 calories per day, then you need to cut only 250 calories out of your diet to achieve your weight-loss goal of one pound per week. For the average person, it takes between 25-50 minutes to burn 250 calories. A precise determination of how long it takes an individual to burn up 250 calories depends on what that person is doing and what his or her body composition is (weight, body fat percentage), but a good estimate can be made by simply counting each minute of non-stressful activity as burning 5 calories. Non-stressful activity includes fairly brisk walking and very leisurely swimming. On a treadmill going all-out at 15 METS, a good estimate of caloric expenditure is 15 calories per minute. Although many aerobic machines indicate that approximately 10 calories are burned per minute even at lower levels of activity, this is frequently an overestimate. To sum up, we recommend estimating that between 5-10 calories are burned per minute depending upon your level of activity, which translates to somewhere between 25-50 minutes to burn 250 calories. Exercise has on-going benefits for weight loss, as well.

When you exercise, you build muscle mass. By increasing your muscle mass (also called lean body mass), you raise your resting metabolic rate, which means that your body burns more calories just to maintain your body temperature and keep vital functions going. And, as you build muscle mass you will notice changes in your body shape. Plus, people who exercise often report feeling better and have a more positive outlook.

You can burn 250 calories by walking at a brisk pace, cycling for about 45 minutes, or running for 20-30 minutes. You can also burn extra calories simply by increasing your activity around the house and in your garden. Find a few different activities that you enjoy, and vary your routine from time to time.

If possible, pair up with someone of similar endurance level. Exercising with a friend can be more fun and help keep you motivated. If you do not currently exercise, consult a physician before initiating an exercise program.

As you begin your weight-loss program, be prepared for a long battle, a battle that is as much psychological as it is physical. Be patient, set realistic goals, enjoy your more active lifestyle, and focus on healthy eating instead of dieting.

Not sure how to cut back on calories? Here are a few tips to help prevent unnecessary consumption:

Sidebar: Taking A Closer Look at Calories and Weight Loss

The relationship between calorie intake and weight management has always been a controversial one. Within the general U.S. public, the number of people who have tried calorie-counting as a means of weight loss — and failed — is surely a very high number.

It should not be surprising that calorie counting has always been a topic of controversy in the field of nutrition. The concept of a "calorie" is a concept that is difficult to understand, in and of itself. When organizations like the American Heart Association, American Diabetes Association, and American Dietetic Association all endorse approaches to weight loss that focus in part on calorie counting and calorie intake, it is not surprising that these public health recommendations are frequently misunderstood or misinterpreted.

What Is a Calorie?

In simplest terms, a calorie isn't any kind of "thing" whatsoever. Calories are not like proteins, or carbohydrates, or vitamins, or any kind of nutrient. You can find protein in food. You can find vitamins in food. Yet, you cannot find a calorie in any food at all. Calories do not exist in that way.

Calories are units of measurement. They are like inches, miles, ounces, degrees of temperature, pounds, tons, gallons, and acres. They are just a way of understanding how much of something is present. In the case of calories, this something is energy. The amount of energy associated with any set of events can be measured in terms of calories. Calories don't have to involve food. For example, there are a specific number of calories that any electrical wire can carry without catching fire. There are a specific number of calories that strike the earth each day in the form of sunlight. Calories are not found in food. They are only related to food insofar as food has the potential to be measured as a form of energy.

Can Food Calories Be Accurately Measured?

Hundreds of internet website post lists of foods and calories. The U.S. Department of Agriculture publishes a searchable online database (http://www.nal.usda.gov/fnic/foodcomp/search/) with calorie information on literally thousands of foods.

Is the information provided by the USDA and other websites accurate? Unfortunately, the answer is both yes and no. Yes, there are solid scientific studies using real foods and real laboratory conditions to support the specific calorie numbers that appear in the USDA database and in other published lists of food and calories This research can be very high quality, sophisticated, and scientifically sound. But it is research based on laboratory analysis — not research based on the passage of real food through a person's digestive tract. Unless food gets digested, it cannot provide us with any calories (energy).

When food calories are measured in a lab, a device called a bomb calorimeter is used. This device measures energy in the form of heat. Within this device, a highly oxygenated, sealed chamber containing a food sample is floated in water. An electrical current is used to ignite the food-oxygen mixture, and as it burns, the water surrounding the floating chamber heats up. The number of calories in the food is determined by the change in water temperature. A high-calorie food gets the water hotter by releasing more heat energy than a low-calorie one.

The human body, of course, is not nearly as simple as a lab device. We don't digest food by setting it on fire. We digest is chemically, and our biochemistry is highly individual — in fact, unique. The calories of energy we obtain (or don't obtain) from food can vary significantly, and some individuals are better matched to one kind of food versus another. Even though calories can be measured accurately in a lab where they appear to be a fixed attribute of food, once we get inside a living person, and a uniquely biochemical digestive tract, all bets are off when it comes to a rigid set of calorie predictions.

How Is Weight Related to Energy?

Our body weight consists of three main components: water, muscle mass, and fat mass. With respect to water weight, we're usually within the vicinity of 60% total weight. A person weighing 150 pounds would be expected to contain about 60% of those pounds, or 90 pounds, in the form of water.

Living, moving, staying warm, and all other body functions require energy. At least some of this energy must come to us daily in the form of food. Other portions of this energy can come from combustion of fat in our fat cells. If our bodies need more energy than we provide ourselves through food, our bodies obtain this needed energy from stored fat. (In certain situations, including emergency situations, our bodies also use starches stored in our muscles and liver and proteins found in the muscles themselves.)

When any component of our total body weight goes down (water, muscle, or fat) while the other components remain steady, we lose weight. When one component goes up to the same extent that another goes down, we remain the same weight. Over time, if our bodies require more energy than we provide ourselves through food, we always lose weight. This "always" cannot be measured in terms of hours, or even a few days. But over the course of time, it is not possible for us to remain the same weight if we maintain the same percent water weight and expend more energy than our digested food provides.

Proteins, Carbohydrates, Fats, and Calories

The laboratory-based rules in nutrition have always been simple: proteins and carbohydrates have traditionally been said to contain 4 calories per gram. Fats have been said to contain 9 calories per gram. This calorie-based description of the three primary macronutrients has been used as the basis for dozens of weight loss programs, especially programs that advocate low-fat, reduced-calorie intake. These programs are based on sound science, but once again, the science is laboratory science, not human digestive tract science.

The reasoning behind these low-fat, calorie-based approaches to weight loss has been simple. Why risk consumption of one macronutrient type (fat) when that nutrient type contains more than twice as many calories (9 per gram) as the other two basic types (protein and carbohydrate at 4 per gram)? While this reasoning seems sound in terms of the mathematics, the successful weight loss experience of many individuals on high-fat, low-carbohydrate diets has seemed to contradict it. But there is not really a contradiction here at all. Individuals are not identical in their digestion. They are differently matched to different foods. Some individuals clearly do better on higher fat, lower carbohydrate diets — even if those diets contain the exact same number of calories as higher carbohydrate, lower fat diets! Figuring out the best dietary balance for your weight management — especially the best balance of proteins, carbohydrates, and fats — is important. It's also a task that is separate and apart from the task of counting calories.

How Do Calories Matter?

If human digestion of food is so individualized and different from the laboratory analyses, do the lab analyses of food calories really matter? Yes, they do! No matter how well matched you are to your weight management meal plan, you simply cannot lose weight if you do not pay any attention whatsoever to portion control and general calorie intake. You cannot lose weight if your body digests food and releases the exact same amount of energy from the food needed to maintain your muscle mass, fat mass, and water weight. In this sense, calories definitely matter. Anyone who stands between 5 feet and 6 feet tall, thinks they can refrain from exercising, eat 5,000 calories' worth of food on a day-in and day-out basis and lose weight is mistaken. Paying attention to calories is worthwhile. A 2009 study by researchers at Harvard School of Public Health and Louisiana State University showed that cutting back on calories, even by as little as 225 calories per day, may be more important than the balance of protein, carbohydrate, and fat in a diet. Studies show that it is possible to go too far, of course, and to cut back further on calories to the extent that healthy weight loss is not possible. At least one study has shown that healthy young women, when cutting back close to the 1,000 calories-per-day level, tend to experience unwanted hormonal shifts and loss of muscle strength, even when protein intake is kept high. That same study showed that young women who reduced their calories — but only to the level of 1,330 calories-per-day — were able to prevent these unwanted changes. But calories aren't the whole story, and it's still important to find the right match of foods for you, and a diet that you truly look forward to eating because of its delicious, attractive, and fresh foods.


A growing body of scientific research confirms the health risks associated with being overweight. For example, in 2001, results of a 10-year research project evaluating health risks in female nurses and male health professionals were published.

Researchers reported that the risk of developing diabetes, gallstones, hypertension (high blood pressure), heart disease, and stroke increased progressively with the level of being overweight among both women and men. The most obese members of the study population were 20 times more likely to develop diabetes than their normal weight peers.

Additionally, both men and women who were overweight but not obese were significantly more likely than their leaner peers to develop gallstones, hypertension, high cholesterol level, and heart disease.

Unfortunately, the fact that the dangers of being overweight and obese are well-documented doesn't make it any easier to lose weight. Many overweight people try every fad diet and prescription medication available for weight loss, and some even resort to stomach stapling or partial stomach removal to help them shed excess pounds.

Unfortunately, only a small number of people who try to lose weight ever attain their weight loss goals, and still fewer are able to keep the lost pounds off for more than 1 year. Many researchers now believe that the key to successful weight loss is to accomplish comprehensive lifestyle changes, a process that involves removing bad habits and replacing them with good habits related to eating behaviors and physical activity.

In addition, lifestyle change must also include the shaping of positive attitudes about oneself and goal-setting. The bottom line? Weight loss is a slow, difficult process, but one that can be made easier if you are ready to address many areas of your life and if you are willing to reach out for support from health professionals, friends, and family members.

Foods Emphasized

A weight-loss diet should include lots of fresh vegetables, fruits, whole grains, and beans. These foods are naturally low in calories and fat, and contain essential vitamins and minerals. They're also rich in dietary fiber, which can help regulate your appetite.

Although restricting high-fat foods can help cut calories, don't limit your intake of fat too much, and take care to include a source of omega 3 fats such as flaxseeds, walnuts, salmon, or halibut in your diet everyday.

Foods Avoided

One easy way to cut calories is to limit your intake of pre-sweetened beverages such as soft drinks, fruit juice, and iced tea and to avoid adding sugar to coffee and tea. Sweetened beverages can contribute lots of extra calories, without providing any nutrients.

Dieters may also want to avoid high-fat desserts and snack foods, as these foods pack lots of calories. Although it is tempting to switch to "fat-free" foods, be aware that these foods often contain a high amount of calories despite the fact that they don't contain fat.

Nutrient Excesses/Deficiencies

Weight loss is nearly impossible without moderate calorie restriction. However, despite calorie restriction, a carefully planned weight-loss diet should include the recommended amounts of all essential vitamins and minerals, fiber, and essential fatty acids.

Avoid weight-loss diets that severely restrict calories, allowing less than 1200 calories per day, unless these diets are part of a medically-monitored weight-loss program.

Who Benefits

Weight loss is beneficial for anyone who weighs more than their ideal body weight. Weight loss is especially beneficial for overweight people who have been diagnosed with any medical condition, most notably adult onset diabetes or cardiovascular disease.

Who is Harmed

As long as weight loss proceeds at a gradual, steady rate (no more than 1 pound per week), following a well-balanced diet, weight-loss does not pose any health risks.

Overweight children, however, should not be placed on calorie-restricted diets unless medically monitored by a primary care practitioner. Instead, children should be encouraged to increase their physical activity and limit the consumption of junk foods.

Menu Ideas

Dieting does not have to be dull and boring! The World's Healthiest Foods, naturally low in calories, high in fiber, and loaded with vitamins and minerals, fit perfectly into a weight-loss plan. See for yourself with the following one-day meal plan below:



For additional weight-loss tips, check out the official web site of the American Dietetic Association at www.eatright.org. For more information on cutting the fat out of your diet, read about the Low-Fat Diet.


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