In last month’s issue I began to explore the reasons why so many people have difficulty maintaining a healthy physique, even when they eat properly and are physically active. I explored the barriers of crash dieting, drug use, and vitamin and mineral deficiencies. This article examines other barriers to successful weight control.
Sleep disturbances are said to affect forty million people in the United States. That figure does not include those individuals who do not suffer from a sleep disorder, but who lose sleep due to worry or who fail to get a full night’s sleep due to the demands of their personal schedule.
An astounding 64 percent of people surveyed by the National Sleep Foundation in 2009 reported having difficulty sleeping at least a few nights each week. 41 percent reported having sleep difficulty almost every night. Half reported that they do not get enough sleep each night to feel their best.
That means that almost two thirds of the U.S. population is not sleeping well. Lack of sufficient sleep is another significant barrier to weight control. Several factors are responsible.
The production of two appetite control hormones is affected by sleep. One of these hormones is ghrelin. Ghrelin is produced by the stomach; it increases the desire for food. The second is leptin, a chemical manufactured by fat cells. Leptin decreases the appetite.
As the amount of sleep decreases ghrelin levels increase, creating a greater desire for food. Simultaneously, leptin levels fall lessening the ability to recognize satiety (fullness or satisfaction). Therefore, lack of adequate sleep has a dual effect on appetite. High levels of ghrelin increase the desire for food and low levels of leptin lead to overeating. The result is an increase in body fat.
A more serious challenge than not getting enough sleep is a condition called sleep apnea, in which a person stops breathing repeatedly during sleep. Individuals with sleep apnea stop breathing for at least ten seconds more than five times in an hour or more than 30 times over the course of seven hours. Those with sleep apnea are prone to substantial weight gain over time.
There are at least two reasons for sleep apnea associated weight gain. The first is that that the irregular breathing pattern causes a significant drop in oxygen levels within the body. This causes the metabolic rate to slow.
The second reason sleep apnea causes weight gain is that the condition causes a decrease in fidgeting during the day. Fidgeting refers to spontaneous body movements that are performed without thinking, such jiggling the legs while sitting or pacing while waiting for an elevator. A 2005 study at the Mayo Clinic found that lean individuals spend 150 more minutes moving each day than do obese people. That is just one of many studies that have demonstrated that the amount of non-purposeful movement performed over the course of the day has a great effect on body fat percentage.
Chronic stress promotes weight gain. Stress is the term that describes all of the demands placed upon the body, whether physical or emotional. The body responds to stress in two ways. If an immediate threat is present epinephrine and non-epinephrine are produced. These hormones prepare for a fight or flight by increasing the heart rate, opening air passages, and increasing energy production.
The response to a sustained threat, such as interpersonal friction in the workplace, is different. Rather than continuing to release fight and flight hormones the body increases the production of cortisol. Unlike epinephrine and nor-epinephrine, which encourage the breakdown of fat to produce energy, cortisol promotes fat storage.
Weight gained in response to elevated levels of cortisol occurs primarily in the trunk of the body. This is the type of weight gain that carries the highest risk for the subsequent appearance of diabetes and high blood pressure.
Another barrier to weight control that is rarely recognized is addiction. Addiction is commonly mentioned when people are struggling with the use of mood-altering drugs, narcotic pain medications, tobacco, or alcoholic beverages, but it is almost never considered a factor in overeating. I believe this is a grave oversight.
The signs of addition are many. They include an intense craving for a specific substance, using more of that substance than intended, an inability to cut back or stop use of the substance, continuing its use despite physical problems, hiding consumption of the substance from others, poor eating habits, and a lack of concern over one’s physical appearance.
I have found that the signs of addiction are commonly associated with foods and beverages containing refined sugars and flours. A story related by a friend illustrates the point. One afternoon she baked a lemon meringue pie. That evening she and her husband each had a piece for desert. The following day she had piece at lunch, but that was followed by another a short time later. She had soon eaten the remaining pieces of pie. Not wanting her husband to know she baked another pie and ate two pieces. Her effort to conceal her dietary indiscretion fell short, however. The meringue on the first pie had not turned out well; that on the second was baked to perfection.
Several of her actions are consistent with addictive behavior: She experienced a craving for the pie, she ate more than she intended, she was unable to stop eating, and she attempted to hide her eating from her husband. For her it was a one-time occurrence that made for a funny story, but many people exhibit an ongoing pattern of behavior that is consistent with addiction to certain foods or beverages.
A significant barrier to weight control is a condition called the metabolic syndrome. The metabolic syndrome is characterized by higher than usual levels of insulin in the body. The high insulin levels are due to insulin resistance - an inability of cells to use insulin efficiently. Insulin converts sugar to fat. As insulin levels rise, the amount of fat deposited increases.
Clues to the presence of insulin resistance are an enlarging waist size, rising blood pressure, a fasting blood sugar level between 100 and 125, a HDL cholesterol level below 40 in a man or 50 in a woman, and a triglyceride level above 150. The presence of any three of these is enough to establish a diagnosis of metabolic syndrome. People who develop insulin resistance often have a family history of type 2 diabetes mellitus and a personal history of frequent hypoglycemic (low blood sugar) episodes.
Thyroid challenges can impair weight control. Clues that thyroid activity is low include the presence of a body temperature less than 97.8 degrees Fahrenheit upon awakening, feeling colder than others, having a pulse rate less than 60 beats per minute, struggling with constipation, having a slow thought pattern, feeling sluggish or tired, experiencing unexplained weight gain, having a depressed affect, developing thin and brittle hair and nails, losing the outer portion of the eyebrows, and snoring excessively.
Thyroid deficiencies are often overlooked by physicians, who have been taught to rely solely upon abnormal levels of the pituitary hormone TSH and the thyroid hormone T4 for diagnosis of and underactive thyroid condition. Abnormal TSH or T4 levels will detect pituitary or thyroid failure, but these are the rarest forms of hypothyroidism (low thyroid activity).
A hypothyroid condition can result from the presence of antibodies that block the action of thyroid hormone in the body. It can also occur when the body is unable to effectively convert the storage form of thyroid, T4, into the active form, T3.
Anti-thyroid antibodies commonly develop in response to an inflammation of the thyroid gland called Hashimoto’s thyroiditis. When anti-thyroid antibodies are blocking the action of thyroid hormone an individual will experience many of the symptoms of an underactive thyroid state. Unfortunately, it may take a decade or more for T4 and TSH levels to fall enough to cause a physician to initiate thyroid hormone supplementation.
T4 and TSH levels will also be in the normal range when the body is not efficiently converting the storage hormone, T4 to the active hormone, T3. Physicians who rely on T4 and TSH levels to diagnose hypothyroidism will never recognize a low thyroid condition that has resulted from the failure to maintain adequate levels of T3.
A barrier to weight control that tends to become more common as people grow older is leptin resistance. Leptin is a hormone produced by fat cells. It was first discovered in 1995. Prior to that time it was assumed that hormone production was limited to specific glands such as the thyroid, pancreas, or adrenal. Several other fat-manufactured substances have subsequently been discovered. One of these is called C-reactive protein.
Fat cells remain fairly constant in number over the course of one’s lifetime. Weight gain is due primarily to increased deposition of fats called triglycerides in the fat cells. As more triglycerides are stored in fat cells levels of leptin and C-reactive protein rise.
The role of leptin in weight control is a relatively recent discovery. Leptin has at least two actions. It tells the brain that an adequate amount of fat has been stored and that appetite may be decreased. It also triggers the breakdown of triglycerides to produce energy.
Unfortunately, as fat cells enlarge levels of C-reactive protein also rise. C-reactive protein binds leptin and prevents it from carrying out its actions. The brain does not get the message to curb the appetite and fewer triglyerides are converted to energy.
A cycle of leptin resistance is created. As more fat is stored C-reactive protein levels rise. C-reactive protein binds leptin and prevents it from doing its job. A feeling of satiety is not produced so overeating occurs. Triglycerides continue to be stored in fat cells rather than being burned for energy. The additional fat storage leads to still higher levels of C-reactive protein and greater leptin resistance, a significant barrier to weight control.
Other fat-produced hormones affect fat storage and weight gain. Another hormone produced by fat cells is adinopectin. Adinopectin plays a major role in the body’s ability to use insulin effectively. It also has anti-atherosclerotic (prevents hardening of the arteries), anti-inflammatory, and anti-diabetic roles. High levels of adinopectin seem to provide protection from coronary artery disease. When adinopectin levels fall insulin resistance is created. This may be one of the underlying causes of the metabolic syndrome. Adinopectin levels have been found to be low in overweight individuals. This promotes additional weight gain because insulin resistance causes more sugar to be converted to triglycerides and stored in fat cells.
A third hormone manufactured by fat cells is glycerol-3-phosphate dehydrogenase (g3pd). Like insulin, g3pd encourages the conversion of glucose (blood sugar) to triglycerides for storage in fat cells. Levels of g3pd are high in overweight individuals.
Age-related hormonal changes often result in an increase in body fat. As the amount of fat increases the actions of leptin are blocked so more food is consumed and fewer triglycerides are burned for energy. Adinopectin levels fall and insulin resistance increases encouraging greater fat storage. G3pd levels rise causing more glucose to be stored as fat rather than being used to produce energy. The result is a progressive rise in the amount of body fat.
When the many barriers to successful weight control are considered it is no longer surprising that many people have difficulty achieving and maintaining a weight that is best for them. A great deal has been learned about mechanisms of fat storage over the past decade, however, and it is now possible to remove nearly all of the known barriers and open the road to successful loss of body fat. In next month’s issue I will present a comprehensive weight control action plan.
© 2010 Wellness Clubs of America.com
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