There are various reasons why people are overweight. These include genetics (suggested by studies of twins), overeating, stopping smoking, alcohol consumption, lack of exercise, a change in life-style, more energy intake than energy expenditure (taking into account resting metabolic expenditure), environmental factors, salt/potassium retention, hidden food allergies, major depression/anxiety/other psychological, medical illness, medications, during and after pregnancy, cultural (perceptions on obesity), and socioeconomic factors.
Obesity, as defined by the Institute of Medicine, is "an important chronic degenerative disease that debilitates individuals and kills prematurely." It continues to contribute to hundreds of thousands of deaths in the U.S. every year.
Set Point Theory. Obesity is not strictly the product of sloth and gluttony. Everybody has a weight that their body can defend and most people know what that weight is. You lose a little weight, but tend to bounce back to your original weight again and again. That weight is called the "set point". Although weight is influenced by what and how much one eats, and by such things as exercise, ordinarily it will revert to its most comfortable level.
One thing that is not well-recognized is the fact that weight loss itself is not a particularly difficult problem. If a human being is put on an 800 or 1000 calorie diet, they lose weight. There do not appear to be a large number of people who have undesirable responses to a 1000 calorie diet that prevents them from losing weight: the few claims that have been investigated have not held up to scrutiny. In other words, there are no people who are totally resistant to weight loss. However, the vast majority of humans are very resistant to the maintenance of a body weight below whatever their set point is.
A person's set point is the approximate weight and fat percentage that their body settles into during adulthood. Body fat is actually regulated by the brain's weight regulating mechanism in the hypothalamus. This mechanism chooses the amount of body fat it considers ideal for the body's needs and then works tirelessly to maintain that level.
The regulating mechanism controls body weight in two critically important ways. First, it has a profound effect of the amount of food you eat. It is responsible for dramatically increasing or decreasing appetite to maintain the set point weight. As you lose weight, it signals hunger; as you gain weight, it reduces appetite. Second, the regulating mechanism can trigger the body's systems to waste excess energy if you overeat or conserve energy if you don't eat enough. Energy conservation may lead to muscle loss and a slow down of the endocrine system due to the body's attempts to protect its fat stores for use in the future. In addition, less muscle mass means the body requires still fewer calories.
An individual's set point is genetically determined. There are those who are able to eat anything and everything they desire and still maintain a low body fat percentage, but others who continually struggle with their genetic set point and constantly diet and exercise to lose weight. Often this weight loss is a loss of both muscle and fat tissue. Once they stop dieting, those who have battled fat loss incorrectly or are simply unable to maintain the proper lifestyle will inevitably return to their original body composition or gain additional body fat. The subsequent weight gain consists primarily of fat tissue.
If you go to a doctor and say that you need to lose weight, the doctor is not likely to tell you that are at your set point, so there is not need to treat you. That thought usually has nothing to do with how people are treated. The diet industry also is not based primarily on medical complications, but cosmetics and profit.
Molecular biologists first identified leptin in 1994. Since then, the fat hormone has been the subject of intense speculation among scientists. Leptin has prompted research into eating disorders, obesity and diabetes. The obesity hormone leptin appears to reduce cravings for sweet foods by targeting taste receptors on the tongue. Therefore, it is possible that a lack of leptin, or the body's failure to respond to the hormone due to defects in leptin receptors (leptin resistance), may contribute to the so-called sweet tooth that affects so many.
Leptin, a hormone produced by fat cells, is involved in weight regulation. It is thought that the hormone signals the brain when fat cells are full, but exactly how the hormone controls weight is not entirely clear. Animals and humans without leptin, or with defective leptin receptors, become obese. As one becomes fatter, the body makes more leptin and the likelihood of leptin resistance increases [NEJM, February 1, 1996;334: pp.292-5]. Men whose bodies produce more insulin also tend to have increased leptin levels.
Exercise decreases the amount of leptin in the blood of both overweight and normal weight individuals. Recent research shows that only 3 hours of exercise per week lowers leptin levels by about 10%. Exercise can lower the levels of leptin no matter how fat a person is. Lowering leptin levels reduces the risk of leptin resistance seen in obesity; raising leptin levels does not appear to be an effective weight loss mechanism in humans. However, trials have shown that large supplemental doses of leptin can result in some weight loss in obese individuals.
In short, leptin levels should be kept within the normal range: low levels can result in food cravings and higher levels tend to suppress appetite but are also associated with tissues becoming less sensitive to the hormone and contributing to craving and more weight gain. Exercise can lower leptin levels, but caution must be taken in some individuals that levels do not go too low. Researchers have long been busy searching for the key to safely control a person's weight. It remains to be seen if they will ever be successful.
Fatigue (especially after exertion), shortness of breath, decreased energy, palpitations, irregular heart beat, edema (especially swelling of the feet and legs), sleep apnea (Pickwickian syndrome) and respiratory obstruction (for obesity to cause sleep apnea and respiratory obstruction it must be severe).
Physical signs and risks of being overweight
Hypertension, coronary heart disease, predisposition to diabetes, hyperlipidemia (increased cholesterol level), metabolic abnormalities, increased risk for gallbladder disease, gout, some types of cancer, and development of osteoarthritis of the weight-bearing joints.
One way to rationalize the treatment of obesity is to treat only individuals who have medical causes and complications. Treat the individual who has hypothyroidism, hyperlipidemia, gall bladder disease, or type II diabetes, to the point where the cause and risks are reduced. Don't treat the obesity itself – treat the cause or the body fat content until you relieve the metabolic consequences. It turns out that just a 10% body fat reduction can produce increases in insulin sensitivity and blood pressure reduction.
Few will disagree that being overweight leads to a reduced quality of life. It is a life where moving, breathing and simply "feeling good" is more difficult; it is a life where doctor visits are more frequent, and the benefits of modern medicine (pills, medications, implanted devices, transplants, replacements, etc.) become essential just for survival.
The relationship of weight to blood pressure. Being overweight is a significant risk factor for the development of hypertension. The prevalence of hypertension in the U.S. is greatly increased by the fact that one quarter to one half of all adults (results differ by study) are overweight. Although the association between higher body fat and blood pressure has been recognized for years, recent studies have discovered a 50-300% higher incidence of hypertension among adults who consider themselves overweight compared to those classified as normal weight. Similar findings are revealed from studies involving children and young adults, in which the connection between weight and blood pressure has been observed to be very strong.
Two proposed mechanisms underlying this correlation are the stimulation of sodium retention and increased catecholamine release, which are results of increased sodium sensitivity and hyperinsulinemia. Age, gender, and race are also part of the equation and so should be considered when studying preventive interventions. Hypertension and obesity treatment are necessary to avoid potential morbidity and mortality from coronary heart disease or stroke.
[Institute of Medicine, Weighing the Options. National Academy Press, 1995]
[American Heart Journal 147 (2004): p.841]
[New England Journal of Medicine Volume 338 (1998): p.1]
[Annals of Internal Medicine 138 (2003): p.24]
[Journal of the American Medical Association 289 (2003): p.187]
The classic 'beer belly' is usually caused by high levels of visceral fat. This is not the same as subcutaneous fat, which lies immediately under the skin. Visceral fat or "gut fat" surrounds the internal organs and causes central obesity.
The more overweight we are, the harder it comes to perform tasks that require fine motor skill such as tying our shoelaces, holding a pencil or tapping a cellphone screen.
The International Diabetes Federation consensus worldwide definition of Metabolic Syndrome (Syndrome X) is as follows:
Central obesity (or a BMI index of over 30) AND any two of the following:
Obesity in both men and women increases the risk for gallstones. This may be a result of lower levels of bile salts relative to cholesterol in the bile causing a higher risk for cholesterol supersaturation and the formation of stones.
Being overweight increases the risk of asthma. [Arch Intern Med 1999;159: pp.2582-8] Obese people with asthma may improve their lung-function symptoms and overall health status by engaging in a weight-loss program. A controlled study found that weight loss resulted in significant decreases in episodes of shortness of breath, increases in overall breathing capacity, and decreases in the need for medication to control symptoms. [BMJ 2000;320: pp.827-32]
Countless studies have demonstrated a strong connection between lack of sleep and increased BMI. Chronically sleep-deprived individuals undergo changes in metabolic hormones that trigger appetite (ghrelin), increase appetite (leptin), and indicate satiety (insulin).
Our indication of whether a person is overweight is based on the BMI (Body Mass Index) calculation. If you perform a lot of non-aerobic exercise then much of your 'excess' weight is likely to be muscle mass rather than fat. In this case, a BMI-based assertion that you are overweight may be untrue.
Studies started reporting in 2009 that children who have their tonsils removed – with or without the adenoids – are at slightly higher risk of becoming overweight.
Traffic fumes and cigarette smoke contain tiny, irritating particles that trigger widespread inflammation and disrupt the body's ability to burn calories for energy and control blood sugar levels.
A study at Columbia University found that children born to mothers living in highly polluted areas were 2.3 times more likely to be obese compared to those in cleaner areas.
Several large studies have found that drinking diet soda actually increases waist size and long-term weight gain. It is theorized that artificial sweeteners trigger sweetness receptors in the brain, which cause the body to prepare itself for an influx of calories. These calories never arrive, confusing our bodies and weakening the link in our brains between sweetness and calories.
2008: A study that followed 3,600 subjects for 7-8 years reported that body mass index and the risk of obesity rose consistently the more artificially sweetened drinks a person consumed.
2015: A study at the University of Texas that followed 749 subjects for 9 years and was published in the Journal of the American Geriatrics Society found that those who drank at least one diet drink a day added a minimum of 3 inches to their waistlines, whereas those who drank no diet drinks at all gained less than 1 inch on average.
2017: A study at Yale University found that when diet drinks or foods are consumed, the brain misreads the number of calories present and reduces metabolism. In other words, the body stops burning energy from food if there is a mismatch between food sweetness and calories.
Predictably, studies backed by the beverage industry disagree with these findings.
Women generally gain 15-40 pounds (7-18kg) during pregnancy, depending on their weight before pregnancy and how many babies they are carrying. Obviously this needs to be taken into account when deciding if weight is a problem for you.
Dr. Brett Jancques, ND reports that all of the obese individuals tested thus far by AAL Reference Laboratories were found to have low growth hormone levels. Testing was accomplished through 24-hour urinary growth hormone measurements. [Townsend Letter, Feb/March 2002, Vol 223/224; pp.74-78]
Some people respond to stress by eating. "Stress Eaters" use food as a drug to deal with external stressors such as work, deadlines or finances. Carbohydrates are often the craved foods because they increase levels of serotonin in the brain, which has a calming effect and helps induce sleep. Stress Eaters often use candy, cookies, pretzels, etc. on the job to relieve stress and are unaware of the reason behind it. A habit of eating in response to stress may lead to obesity.
Even if you never become diabetic, high levels of insulin contribute to cardiovascular risk by increasing the process of atherosclerosis. Insulin increases the rate at which cholesterol-laden plaque builds up on arterial walls. The abnormally high levels of insulin produced by all overweight individuals, diabetic or not, is an independent risk factor for early cardiac death.
Obese individuals often experience delayed wound healing due to a number of factors including: reduced oxygen, nutrient and blood supply to the wound site; moisture and microorganism collection in skin folds that decreases skin integrity and increases risk of infection; immobility, skin friction and skin shear impair the skin's barrier function.
Women who are obese often experience amenorrhea as a result of excess fat cells interfering with the process of ovulation.
Chronic menorrhagia and PMS is usually the result of deficient progesterone secretion or constant adipose-released estradiol from obesity or recent substantial weight loss.
Obese and underweight persons are more often depressive than people in the normal body weight range.
Forcing joints to carry more weight than they were designed for often results in premature failure.
Scientists have discovered a hormone that may explain the link between diabetes and obesity – a tantalizing finding that could someday lead to new treatments for the disease. The hormone, dubbed resistin, is produced by fat cells and prompts tissues to resist insulin, the substance the body needs to process blood sugar, researchers reported in the scientific journal Nature. Diabetics produce too little insulin or cannot use it efficiently. This will probably result in new drug treatments, but emphasizes the need for weight reduction.
Women with 'apple-shaped' bodies may be more likely to develop breast cancer than their 'pear-shaped' counterparts. Harvard researchers studied breast cancer risk among postmenopausal women who had never used hormone replacement therapy (HRT) and found even greater risks, with larger-waisted women appearing to be 88% more likely to develop breast cancer than smaller-waisted women. HRT use can increase the risk of breast cancer, regardless of waist size. Exactly why fat distribution affects breast cancer risk is not fully understood but perhaps, the researchers speculate, upper or central body fat is deeper and may be closer to the important organs and glands that regulate hormone balance than fat in the other areas of the body. These hormonal changes may be responsible for the increased risk of the cancer. [American Journal of Epidemiology December 1999;150: pp.1316-24]
Apart from excess stimulation by estrogen in breast and ovarian cancer, obese people are more prone to cancer, although it is still uncertain why.
At least two studies have found that obesity significantly increases one's risk of developing pancreatic cancer. [JAMA. 2001;286: pp.921-929]
Examples of cancers linked to obesity are breast and ovarian cancer – it is thought that the excess estrogen produced by obese patients increases their chance of developing hormone-sensitive versions of these cancers.
Researchers used data from a study of lung cancer patients in New York from 1982 to 1985. They focused on patients who had never smoked, or those who hadn't smoked in the last 10 years, then took into account physical data on patients' heights and weight. Researchers found that study subjects who were at the most extreme levels of obesity had the highest risk of lung cancer. The study is a first for linking being overweight to lung cancer; it has previously been shown to play a role in breast, uterine, and colon cancer.
Researchers are unsure why being obese plays a role in lung cancer; some researchers suggest it's related to hormones such as higher levels of estrogen and insulin. In addition, being overweight puts an added strain on the lungs, reduces lung capacity, and increases asthma risk. [American Journal of Epidemiology Sept. 2000]
Contrary to commonly reported stories, 3 months of intermittent or continuous treatment with an ephedra-containing weight-loss product containing ephedra (but not caffeine) had no ill effect on heart rate or blood pressure and there were no cases of serious adverse effects reported in a well-controlled study of 279 healthy, overweight people. 33% of patients on intermittent treatment and 48% on continuous treatment experienced adverse effects deemed non-serious such as dry mouth, headache, insomnia, nervousness, agitation, constipation and/or diarrhea. [Experimental Biology 2002, April 20-24, 2002, New Orleans, LA, USA. Abstract]
The sad thing, according to the director of nutrition for the Center for Science in the Public Interest, is that "people keep believing that the magic bullet is just around the corner... if they only eliminate food 'X' or combine foods 'A' and 'B', or twirl around three times before each meal." The reality is that most ordinary people lose weight without the gimmicks Americans spend $30 billion a year on. [Annals of Internal Medicine 119 (1993): p.661]
In the largest survey ever undertaken on the long-term maintenance of weight loss, Consumer Reports found that the vast majority of the most successful dieters said they lost weight entirely on their own, without enrolling in some expensive program, or buying special foods or supplements or following the regimen of some diet guru [Consumers Union news release, 6 May 2002]. The most popular fad diet right now may be Atkins, but it's not the most popular diet, and not the one that seems to work the best.
To lose weight, you can either cut down on calorie intake by restricting the amount of food you eat, or you can transition away from eating junk food (foodstuffs long on calories but short on nutrition) toward eating food that is nutrient-dense, but relatively calorie-dilute: foods such as fruits, vegetables, beans and whole grains.
Vegetable juicing increases not only the quantity of vegetables that you will eat, but also the absorption of their nutrients. Nutrient deficiency, a common problem with dieting, is thereby overcome. Fresh vegetable juice also helps lower calorie consumption because it reduces or replaces other foods that you might have eaten instead. Juicing helps normalize weight, sometimes without a forced reduction in calorie consumption. Juicing also promotes a feeling of being energized. It is as though energy would rather be burned than converted to fat.
You can increase your metabolism significantly by using hot and spicy foods such as hot peppers (of all varieties) and mustards. Research shows that these foods increase your metabolism. Try substituting mustard for mayonnaise and add hot peppers to your food for greater flavor and increased metabolism. Cayenne may promote weight loss in those with a low basal temperature.
Permanent weight control is difficult to achieve. Between 95% and 98% of repeat dieters fail, regaining the weight that they initially lose. What about the other 2-5%? In her book "Eating Thin for Life," award winning journalist and dietician Anne Fletcher delved into the habits of a few hundred people who had not only lost an average of 64 pounds but also maintained that loss for an average of 11 years. What did she find? "Basically, they're eating the opposite of a high-protein, low carbohydrate diet," Fletcher reported. When she asked them to describe their eating habits, the top response was "low-fat" followed by "eating less meat." These dieters with long-term success also told her they ate "more fruits and vegetables."
Recent research supports this notion. One research study showed that significant weight loss can be triggered by just feeding people extra fruit – 3 added apples or pears a day [Nutrition 19 (2003): p.253]. Harvard studied 75,000 women for a decade and the results suggest that the more fruits and vegetables women eat the less likely they will become obese [American Journal of Clinical Nutrition 70 (1999): p.412]. A 2004 review of the available research suggests that in general "increasing fruit and vegetable intake may be an important strategy for weight loss." [Nutrition Reviews 62 (2004): p.1]
The results of the biggest study on diet and obesity to date was released in 2003, comparing over a thousand vegans to tens of thousands of meat-eaters, and lacto-ovo vegetarians [International Journal of Obesity 27 (2003): p.728]. The meat-eaters were on average significantly heavier than the vegetarians, who were significantly heavier than the vegans. Even after controlling for exercise and smoking and other nondietary factors, vegans came out slimmest in every age group: fewer than 2% of vegans were obese. In a snapshot of the diets of 10,000 Americans, those eating vegetarian were slimmest whereas those eating the fewest carbs in the sample weighed the most. [Journal of the American Dietetics Association 1010 (2001): p.411]
Researchers at the National Cancer Institute followed over 75,000 people for ten years to find out which behaviors were associated with weight loss and weight gain. The one dietary behavior most associated with an expanding waistline was high meat consumption and the dietary behavior most strongly associated with a loss of abdominal fat was high vegetable consumption. Even after controlling for other factors, men and women who ate more than a serving of meat per day seemed to be 50% more likely to suffer an increase in abdominal obesity than those who ate meat just a few times a week. The researchers conclude: "Our analysis has identified several easily described behaviors [such as reducing meat intake to less than three servings per week and jogging a few hours every week] that, if widely adopted, might help reverse recent increases in adult overweight... Increases in vegetable consumption might reduce abdominal obesity even further." [American Journal of Public Health 87 (1997): p.747]
Obesity is a major contributor to many serious illnesses, and is much less common among vegetarians, compared to the general population. Vegetarians are, on average, about 10% leaner than omnivores.
Reducing fat in the diet may reduce cancer risk and, in helping weight control, may reduce the risk of heart attacks and strokes. [The National Cancer Institute booklet, "Diet, Nutrition, & Cancer Prevention: A Guide to Food Choices"]
An increasing number of studies suggest that any water-soluble fiber may help people lose weight. High fiber foods are bulky, low in calories, and take longer to chew contributing to weight loss and maintenance. Both types of fiber also help to create a feeling of fullness from meals (resulting in fewer calories being consumed from calorie-dense fats and sweets), stabilize blood sugar and maintain energy levels.
Good results in weight loss studies have been achieved with guar gum, a water-soluble fiber obtained from the Indian cluster bean (cyamopsis tetragonoloba). In one study, nine women weighing between 160 and 242 pounds (73 to 110kg) were given 10gm of guar gum immediately before lunch and dinner. They were told not to consciously alter their eating habits. After two months, the women reported an average weight loss of 9.4 pounds (4.3kg) – over 1 pound per week.
An excellent book to read on the benefits gained from an adequate (not high) protein diet is "Protein Power: The High-Protein/Low Carbohydrate Way to Lose Weight, Feel Fit, and Boost Your Health-in Just Weeks!" by Michael and Mary Eades.
More and more researchers are citing insulin as the main culprit in weight gain and expound the benefits of a diet low in carbohydrates. Carbohydrates – in particular rapidly-absorbed simple carbohydrates (sugars) – stimulate the body to store fat, thus making weight loss difficult. Researchers have found that eating larger portions of protein in conjunction with severely reduced portions of carbohydrates causes people to burn the excess fat stored in their bodies.
Despite their caloric density, a 2003 review of all the research on the matter concluded eating nuts every day might actually help one maintain or even lose weight. [American Journal of Clinical Nutrition 78 (2003): p.647s]
Studies in coconut eating countries have shown a higher metabolic rate in both men and women than in the general US population.
October 2014: A study by scientists at Edinburgh and Southampton universities and published in the journal Diabetes has shown that moderate sunlight exposure causes the skin to release a gas called nitric oxide, which in turn helps regulate metabolism and slow weight gain.
Increased physical activity lowers the risk of obesity, favorably influences the distribution of body weight and has a variety of health-related benefits, even in the absence of weight loss. Exercise is the natural partner to weight loss. You will discover improvement in balance, energy level, immune function, muscular strength, reflexes, and self-esteem.
7-Keto DHEA supplements, at a dose of 200mg per day in adults 25 to 55 years of age has been shown in a double-blind trial to enhance weight loss, aid in the reduction of body fat and effect thyroid hormone levels. This two-month study also demonstrated that 7-Keto does not significantly affect blood sugar, testosterone, estradiol, liver or kidney function.
How much DHEA we maintain may be involved in determining how fat is actually stored in the body. In another study, DHEA was given to five male, normal weight subjects at a dose of 1600mg per day, divided into 4 doses. After 28 days, with diet and physical activity remaining normal, 4 of the 5 exhibited a mean body fat decrease of 31% with no overall weight change. This meant that their fat loss was balanced by a gain in muscle mass characteristic of youth. At the same time, their LDL levels fell by 7.5% to confer protection against cardiovascular disease.
7-Keto DHEA does not become converted to sex hormones as DHEA does. The choice of whether to use DHEA or 7-Keto DHEA will be influenced by your sex and adrenal hormone status. Laboratory testing is required to determine this.
Masked food allergy can be a factor in the development and persistence of obesity. [Abstract. J Lab Clin Med 32: p.1547, 1947]
A 3-month double-blind study of 122 moderately overweight people found that 400mcg of chromium daily resulted in an average loss of 6.2 pounds (2.8kg) of body fat, as opposed to 3.4 pounds (1.5kg) in the placebo group. There was no loss of lean body mass. These results suggest that chromium can help you lose fat without losing muscle.
However, six smaller double-blind placebo-controlled studies found chromium picolinate supplements produced no weight loss or change in lean body mass. These conflicting results may be due to differences in study size, the dosage of chromium, and the individuals enrolled. Overall, chromium does appear to be promising.
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