Why Weigiht is regained after diet

Maintaining Weight Loss and Avoiding Weight Loss Plateaus

The fact that the tendency to be overweight or actually obese runs in families together with the fact that in most adults body weight is constant over long periods of time despite changes in both food intake and exercise suggests that our body weight is controlled by many factors beyond most people’s control. Despite eating more than 1 million calories a year, the balance of calories in and out varies no more than 1% over the year. The control mechanisms for body weight that regulate how ability to lose and even more important maintain our weight are based on inherited factors based down from past generations.

Most individuals who have lost weight and only to regain it know its easier to lose weight than to keep it off. Why is this so difficult? Its due to the fact that as one loses weight there is a decrease in metabolism and energy expenditures to values below what one might suspect from the actual weight. Part of this is due to the reduction in muscle mass seen with weight loss. This is also the explanation for the weight gain with aging- i.e. everyone loses muscle and bone mass as they age and the causes of plateaus in all weight loss programs. However, this metabolism reduction is still not enough to explain the easy and quick weight regain often to levels about the starting weight as well as the reason for weight loss plateaus after losing 15-20 lbs.

Typical Weight Loss Plateau in Diet Program

Weight Loss Plateau

Reduced metabolism that characterizes plateaus and weight maintenance is accompanied by increase hunger. Fullness is often hard to achieve after weight loss. People tell me all day how hungry they are after they have attained their weight loss goals. Other issues contributing to  weight loss plateaus include gradual weight regain after a weight loss programs is the fact that calories burned with any movement are very dependent on body weight.

Here are the reason for weight loss plateaus and the difficult maintaining weight loss after a diet plan:

1. Reduced metabolism–occurs during dieting and persists for months after the weight loss!
2. Increased hunger–occurs during all weight loss programs
3. Boredom–often interfers with all attempts at weight loss
4. Reduction in calories burned during physical activity–due to fact that most exercise is weight dependent

calories burned depend on body weight

Note in the table on the left the calories burned during any activity is dependent on body weight. A 200 lb person will burn 243 calories walking at 3 mph, while a 130 lb person will burn only 118 calories walking the same distance which is about a mile.


What is a SET POINT?   Your set point is a number  on the scale where your weight seems to hover around. Set points cause weight to slow down producing plateaus.

What determines a set point?  Your genes, age, body weight, gender, exercise.

How is the set point set higher?  Gradual weight gain  with aging, menopause, overeating, inactivity leads  to higher and higher set points. If maintained too
long, the new, higher weight becomes permanent.

How to lower your set point?
Gradual weight loss over time  can lower it.

When does the set point stop weight loss? Most  people can lose 15-20 lb before the set point stops  weight loss producing a plateau lasting weeks to months.

How to Prevent Regaining Your Weight After Dieting

Regain weight after diet is the most common response following a “successful” diet.  This is caused by a compensatory slowing of the metabolism and an increase in hunger during the diet that can persist for years after the initial weight loss. The progressive slowing of metabolism occurs no matter how the weight loss was produced–traditional calorie restricted diets, low carb, high or low fat foods, medication, and even gastric bypass. It occurs with or without exercise and in the face of maintaining limited calories after the initial dietary period. A recent report showed that 1/3 or more of the “Biggest Losers” on NNC-TV regained their weight.

What is Successful Weight Loss?

Successful weight loss is keeping at least 10% of the body weight off for at least one year (this definition differs with the FDA, who state that an effective weight loss drug only has to produce a 5% loss. Many  researchers find that only 10-20% of overweight individuals are able to obtain the goal of “successful weight loss”. This occurs no matter what diet or exercise plan is employed.
The figure below is adapted from Sumithran, P et al from New England Journal Of Medicine (2011:365:1597-1604). It shows the regain of weight following 10 weeks of diet and weight loss despite eating calories calculated for weight maintenance.

Why Weight is Regained after Weight Loss: Marked Increase in Hunger After Weight Loss Program

The reason why 90% of dieters regain their weight within a year is not the result of a lack of willpower, but the fact that hunger is increased during and after weight loss. These changes continue for several years after, during which time the body tries to regain its lost weight. Studies have shown that this is due to a rise in the levels the hormones and chemicals causing hunger including Grehlin, and gastric inhibitor polypeptide.

Why Weigiht is regained after diet
The changes in hunger perception during and after weight loss are well-illustrated in the studies of Dr. Sumithran and colleagues in the graph below. They evaluated hunger before and during a weight loss program and during the maintenance phase by providing a standardized meal and measuring the degree of hunger reported by the subjects over the following six hours.
In the graph, the solid black dots illustrate the hunger patterns for four hours after eating a standard meal before the weight loss. Hunger starts off at 32, drops 30 minutes after eating to almost zero, then gradually increases over the next 120 to 240 minutes, ultimately reaching levels experienced before the meal.

*Hunger Persists for More than a Year After Weight Loss

Hunger is increased after weight loss

For subjects on their 10th week of the diet, the clear boxes show increased hunger before the meal (as would be expected) which persisted for four hours after the meal. The triangles show an increased hunger pattern before and after a meal when the subject returned to “normal eating” a year after the weight loss. These values are similar to the hunger patterns seen during the dietary phase.
This pattern of increased hunger after completing a weight loss program may be one of the reasons for the common difficulty of maintaining weight loss after most diets, as well as the need for continued treatment after the initial weight loss—either surgical or with medication.


Summary of Causes of Weight Loss Plateaus and What You Can Do About It:

Weight Loss Plateaus Miami 33143

Read more About How Successful  Dieters Maintain their Weight Loss. from actual weight loss maintainers Dr Lipman has treated.









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  • Can someone w Hypothyroid Hashimotos lose weight and maintain it? How?

    • Dr. Richard Lipman M.D.

      Of course, all you need to do is to make sure your thryoid function is normal with a simple, inexpensive TSH blood test. If you need thryoid medication, taking the pills should normalize your metabolism.

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