CSN-CommunityPost-Why do so several people regain weight after going on a diet?

Anyone who has decided to lose weight and keep it off understands how difficult the task can be. It looks as though it should be simple: Exercise to burn calories and decrease your calorie intake. But many types of research have shown that this straightforward strategy doesn't work correctly for the vast majority of people.

An example of the challenges of managing weight loss comes from the current National Institutes of Health research. The investigators followed 14 participants who had participated in the "Biggest Loser" reality show. Throughout the 30 weeks of the show, the participants lost an average of above 125 pounds per person. However, in the six years after the reality show, all but just one gained back their lost weight, despite exercising and diet.

Why is it so difficult to lose weight and keep it off? Weight loss often tends to declines in our resting metabolic rate — how many calories we burn at rest, making it hard to keep the weight off. Why does weight loss cause resting metabolism to go down, and is there a way to maintain an average resting metabolic rate after weight loss? As a person who researches musculoskeletal physiology, I will try to answer these queries.

Activating muscles deep in the leg that helps keep fluid and blood moving through our bodies is essential to maintaining a resting metabolic rate when we are standing or sitting quietly. The function of these muscles, known as soleus muscles, is a primary research focus for us in the Clinical Science and Engineering Research Center at Binghamton University. Usually called "secondary hearts," these muscles pump blood back to our heart, allowing us to maintain our average metabolic activity rate during sedentary activities.

Metabolism and weight maintenance: Resting metabolic rate (RMR) refers to all of your body's biochemical activity when you are not exercising. It is this metabolic action that keeps you alive and breathing.

Calmly sitting at room temperature is the regular RMR reference point related to one metabolic equivalent or MET. A gradual walk is regarding two MET, jogging seven MET, and bicycling four MET. While we want to move around a bit to complete daily living tasks, we tend not to move very much in modern life. For most people, 80% of the calories we expend every day are because of RMR.

Your RMR should fall a small quantity when you lose weight as you are losing muscle tissue. However, when most of the weight loss is fat, we would expect to see only a tiny drop in RMR because fat is not metabolically very active. What is unexpected is that relatively large drops in RMR are widespread among people who lose body fat through exercise or diet.

The "Biggest Loser" contestants, like, experienced a decrease in their resting metabolic rate of nearly 30% even though 80% of their weight loss was because of fat loss. A simple calculation reveals that making up for such a massive decline in RMR would need to add almost two hours in a day of brisk walking, seven days a week, on top of a person's regular activities. Many people cannot fit this activity level into their lifestyle.

No question eating a balanced diet and regular exercise is right for you. Still, from a weight-management perspective,\raising your resting metabolic rate may be the more efficient strategy for losing weight and managing that lost weight.

RMR and your heart

Metabolic actions are dependent on oxygen delivery to the tissues of the body. This happens through blood flow. As an outcome, cardiac output is a primary determinant of metabolic action.

The adult body includes about four to five liters of blood, and all of this blood circulates throughout the body every second or so. The quantity of blood the heart can pump out with every beat is based on the amount of blood returned to the heart within beats.

If the "plumbing" of our body, particularly our veins— was composed of rigid pipes and our legs' skin was tough such as bird legs, cardiac outflow would always equal to cardiac inflow, but this is not the situation. The veins in our body are pretty flexible and can expand their resting size many times. Our soft skin also supports lower-body volume expansion.

As a result, when we sit quietly, blood and interstitial fluid (the fluid surrounding all the cells in our body) pool in the lower parts of the body. This pooling significantly decreases the amount of fluid returning to the heart and, correspondingly, reduces how much juice the heart can pump out during every contraction. This decreases cardiac output, which dictates a reduced RMR.

Our research has shown that cardiac output will drop about 20 percent for typical middle-aged women when sitting quietly. The fluid-pooling situation can be more significant for individuals who have recently lost weight because their skin is now extremely looser, providing more space for fluids to pool. This is particularly the state for people undergoing rapid weight loss because their skin has not had time to contract.

Raising metabolic activity:- For young, healthy individuals, this pooling of fluid when sitting is limited because specialized muscles in the legs' calves — the soleus muscles — pump blood, and interstitial fluid return to the heart. This is why soleus muscles are usually referred to as our secondary hearts. Our modern, sedentary lifestyles indicate that our secondary hearts lead to weakening, which permits extreme fluid pooling into the lower body. This condition is now commonly called "sitting disease."

Further, excessive fluid pooling can generate a vicious cycle. Fluid pooling decreases RMR, and lowered RMR means less body heat generation, which ends in an additional drop in body temperature; people with low RMR often have persistently cold hands and feet. Because the metabolic action is strongly dependent on tissue temperature, RMR will accordingly fall even more. A fall of just one degree in body temperature can produce a 7 percent drop in RMR.

One logical, expensive approach to decreases fluid pooling after weight loss would be to experience cosmetic surgery to remove extra skin to reduce the fluid pooling space created by the weight loss. Indeed, recent research has confirmed that people who had body-contouring surgery after losing considerable volumes of weight based on gastric banding surgery had more excellent long-term control of their body mass index than somebody who did not have a body-contouring operation.

What can you do?

A very convenient way of maintaining RMR during and after weight loss is to train your soleus muscles or secondary hearts. The soleus muscles are postural muscles and so need training of long duration and low intensity.

Tai chi, for instance, is a practical approach to accomplish this. But, we've observed that many people find exercises onerous.

Over the previous several years, researchers in the Clinical Science and Engineering Research Lab at Binghamton University have worked to produce a more practical method for retraining the soleus muscles, forming a device, available by a university spinoff company, that uses a specific mechanical vibration to activate receptors on the sole, which in turn causes the soleus muscles to undergo a reflex contraction.

In a research of 54 women between the ages of 18 and 65, we found that 24 had secondary heart insufficiency pointing to excessive fluid pooling in the legs. For those women, soleus muscle stimulation pointed to a reversal of this fluid pooling. The capability to prevent or reverse fluid pooling, allowing a person to maintain cardiac output, should, in theory, help these people maintain RMR while doing sedentary activities.

This premise has been verified, in part, by recent researches undertaken by our spinoff venture. These unpublished studies show that cardiac output can be raised back to normal levels by reversing fluid pooling. Study results also indicate that by increasing cardiac output back to natural resting levels, RMR returns to natural levels while individuals are sitting peacefully. While this information is preliminary, a larger clinical trial is currently underway