Here’s a great article on how to lose weight and keep it off from Johns Hopkins Health Alerts.

The National Weight Loss Registry study proves you can lose weight and keep it off without going to extremes.

Set point theory

According to this theory, you have a predetermined weight and level of body fat—called a set point—that your body wants to maintain.

This body fat level is determined by genetics, just like your height.

Exactly how the body controls its fat stores is unknown, but the regulatory mechanism, sometimes called the adipostat, (like a thermostat for fat) is located in the brain. The adipostat monitors the body’s fat stores, possibly through the actions of the hormone leptin, and works to maintain the set point by adjusting appetite, physical activity, and resting metabolic rate to conserve or expend energy. Thus, eating and physical activity may be subtly controlled by the set point mechanism.

Metabolism continued

Whether or not obese people have an abnormally slow metabolism is controversial.

In fact, it takes more energy to maintain a greater body mass. For example, a person who weighs 200 lbs has a higher resting metabolic rate than someone who weighs 150 lbs.

In addition, the 200-lb person expends more calories than the 150-lb person for any given physical activity. But even when people of the same height, weight, age, gender, and muscle mass are compared, their resting metabolic rates vary by 20% or more.

This means that if you are predicted to use 1,200 calories through your resting metabolic rate, you may actually use anywhere from 1,080–1,320 calories. This variability explains in part why two people who weigh the same may require different amounts of calories to maintain, lose, or gain weight.

It’s important to remember that whatever your resting metabolic rate, if you consume more calories than you expend, those extra calories will be stored primarily as fat.

This will happen regardless of whether the extra calories come from fats, carbohydrates, or proteins (although dietary fat is converted into body fat more efficiently than dietary proteins or carbohydrates).

For more information on metabolism and how it is possible to boost it, see the Metabolism section of this site.

 Metabolism
This is the process that extracts and utilizes energy (measured in calories) from food. Even at rest, energy is needed for many functions, such as breathing, the beating of your heart, and cell growth and repair.

The amount of energy used for these basic functions while you are at rest is known as your “resting metabolic rate,” which accounts for approximately 70% of your body’s use of energy each day. The rest is taken up with the physical exercise you do each day to expend calories. The more activity, the more likely you will be to lose weight, but your metabolism can be a trick beast to deal with.

Your resting metabolic rate is affected by your weight, age, level of physical activity, and the amount of muscle in your body. Having more muscle increases your metabolic rate, since muscle utilizes more energy than fat, even at rest.

This is why people who used to be athletes often pack on the pounds when they stop competing, and why many of us start to suffer from ‘middle aged spread.’

Your resting metabolic rate is also in part genetically determined.

The act of eating also uses up energy, because energy is needed to digest food, absorb nutrients, and store excess calories as body fat. This process—called thermogenesis—accounts for 10–15% of the body’s total daily energy expenditure.

Some research suggests that obese people require slightly less energy for thermogenesis than normal-weight people, and thus more of the calories they eat are stored as fat rather than used to process food.

Genes

A number of genes are responsible for regulating body weight.

More than a decade ago, researchers at Rockefeller University discovered that mutations in a gene called the obesity (ob) gene prevented a strain of mice from producing leptin.

Leptin is a hormone normally manufactured by fat cells, and released into the blood to inform the brain about the body’s level of fat stores.

When this communication system works properly, the brain responds to leptin by reducing a person’s appetite and speeding up metabolism to maintain a normal level of body fat.

Because the mice with the mutated ob gene did not produce leptin, their brains continually sent messages to the rest of the body to eat and store fat, and the mice  became obese.

However, when leptin was injected into the obese mice, they quickly lost weight through a combination of decreased food intake and increased activity.

Since this discovery, however, researchers have found that administering leptin to obese people rarely reduces weight, because their blood leptin levels are already high.   It can also be because they have gone for so long not feeling full, that their eating habits are automatic and thus not easily undone.

Still, unraveling the link between leptin (and other substances released by fat cells) and weight may lead to the development of more effective drugs for weight loss by deaing with the center of the brain that signals satiation and fat storage.

Factors That Cannot Be Changed
Although these factors are beyond your control, their impact on your weight can be modified by changing your diet, and increasing your level of physical activity.

Being vigilant about what you eat, when, and why, can stop you from consuming a large number of calories in a mindless manner.
If you don’t consume them in the first place, these factors will not have as much of a chance to kick in and provide you with an uphill struggle to lose weight and keep it off.

Heredity
Studies show that 80% of children born to two obese parents will themselves become obese, compared with 14% of children born to normal-weight parents. Research on identical twins shows similarly high rates of inheritance.

However, studies comparing the weights of adoptees with the weights of their biological and adopted parents indicate that genetic factors are responsible for only about a third of the difference in weight.

Heredity seems to influence the number of fat cells in the body, how much and where fat is stored, and how much energy the body uses at rest (your metabolism)

In addition, childhood obesity tends to translate into adult obesity.

About 80% of obese children become obese adults (although only about 20% of all obese adults were obese as children).

At present, we have more obese children than ever before, and they are even manifesting metabolic syndrome, insulin resistance, Type 2 diabetes, and even high cholesterol. Clearly something has happened to America’s diet for this to be so pervasive.

Even if the genetic and metabolic components involved in weight regulation are mostly beyond your control, the environmental factors ARE controllable and can have a significant impact. It has been proven that family and friends contribute to our growing weight problem, as do attitudes and emotional responses to food.

By manipulating the controllable factors to your advantage, you can successfully lose weight, and keep it off, without a ton of potions and pills.

Factors That Affect Body Weight
Controllable factors—for example, a high-calorie diet, emotional responses to food (such as eating when anxious or bored), and a lack of exercise—play a critical role in the development of obesity.

Yet research confirms that more is involved in losing weight and keeping it off than just a lack of willpower, emotional upset, or a sedentary lifestyle.

There are also the factors that can’t be changed, and deal us a hand with regard to our body type and weight which can be difficult to overcome.

Good nutritional habits aren’t just important for preventing diseases.  They can also help you control your weight, or even lose weight.

It is a sad fact: the number overweight and obese people, including those who can be categorized as ‘morbidly obese’, are higher than ever in the United States.

Morbidly obese means so overweight, they are at risk of death.

According to the CDC, more than six in 10 American adults are overweight or obese—and most adults are about 25 pounds heavier than people were in the 1960s. Clearly, living in the land of plenty has proven to be a mixed blessing.

To make matters worse, more than half of all overweight people actually think they’re at a healthy weight, according to a recent Associated Press poll.

In theory, weight control is a simple matter of balancing energy intake (the calories supplied by food) with energy output (the calories expended by physical activity, the digestion of food, and the functioning of your body).

To lose weight, you need to burn more energy than you take in.

In practice, however, the task is not that simple. While the basic principle of energy balance remains true, several mechanisms—genetic, metabolic, and environmental—can affect how much you eat, and how your body uses and stores energy.