body of evidence suggests low-calorie sweeteners offer little
help to dieters and may even help promote weight gain. Low calorie
sweeteners may increase appetite for sweet foods, disrupt the
body's ability to accurately assess caloric intake, blunt thermic
response, promote overeating, and lead to weight gain.
Hampton T (2008). Sugar substitutes linked to weight gain.
JAMA. May 14;299(18):2137-8.
Sources of Stored Energy
Body fluids (glucose or lipid)
Liver & muscle glycogen
How Body Regulates Weight
- Complex homeostatic system
- Hypothalamus is central coordinating area
- Many homeostatic molecules involved in hunger and satiety
- Glucagon-like peptide-1
- Neuropeptide Y
- Corticotropin releasing hormone
- MCH (melanocortin-concentrating hormone)
Major Hormones Regulating Lipolytic Activity
Genetics and Obesity
The direct genetic effect on obesity is estimated to be 25-40%.
Indirect genetic factors raises the genetic effect to approximately
70% of the cause of obesity. Over 24 genes associated with obesity
have been identified.
The weight of adults adopted as children is related to their
natural parents and not their adoptive parents.
Pairs of twins gained or lost very similar amounts of body
weight when overfed or underfed a 1000 kcal per day. The weight
gain or loss between different pairs of twins was quite different.
In a 100-day study, the weight gain on an extra 1000 kcal ranged
from 3-14 kg.
Bouchard C, Tremblay A, Despres JP, Nadeau A, Lupien PJ,
Theriault G, et al. The response to long-term overfeeding in
identical twins. N Engl J Med 1990;322:1477-82.
Cutbacks in mandatory physical education at school has contributed
to an overall decline in children's physical activity levels.
When these programs are available, they often involve little
actual physical activity and do not focus on the fun aspects
of physical activity. Also see Importance
of Recess in School.
U.S. Department of Health and Human Services, Physical
Activity and Health: A Reports of the Surgeon General, U.S. Dept.
of HHS, Atlanta, GA, 1996.
Sleep and Weight Management
little sleep may cause weight gain by way of two hormones. Firstly,
lack of sleep may decrease levels of leptin residing in fat cells.
Lowered Leptin levels can block feelings of satiety and encourage
eating more. Secondly, sleep depravation increases ghrelin in
the gastrointestinal tract, which stimulates appetite.
Sleep Deprivation and Obesity
"Sleep Deprivation can cause physiological distress,"
said Dr. Sateia, a former president of the American Academy of
Sleep Medicine. "This may include impairment in immune function
and in carbohydrate metabolism. There is some interesting work
suggesting that sleep deprivation may be associated with disturbances
in appetite regulation and conceivably contribute to obesity,"
Lack of sleep has been linked to obesity, depression, diabetes,
and cardiovascular disease. However, other factors may be responsible.
People who don't get enough sleep also tend to eat more fast
food which could account for longer term problems rather than
lack of sleep per se, reported Mindy Engle-Friedman of the City
University of New York at the annual meeting of the Asssociated
Professional Sleep Societies in Minneapolis in June 2007.
Weight Loss & Knee Pain
Obese people are more sensitive to pain than non-obese people.
Charles E (2005). Study of older adults suffering from
osteoarthritis of the knee. American Psychosomatic Society, Denver.
Women who lost an average of 11 lbs decreased their risk for
knee arthritis by 50%.
Felson DT, Zhang Y, Antony JM, Naimark A, Anderson JJ (1992).
Weight loss reduces the risk for symptomatic knee osteoarthritis
in women: The Framingham Study. Ann Intern Med. 116:535-539
Caffeine & High Carb Diet
A high carbohydrate diet negates the metabolic effects of
caffeine, such as increased mobilization and oxidation of fatty
acids, during exercise.
Di Pasquale (2004) SWIS Conference.
Type II Diabetes
II diabetes accounts for 95% of all diabetes cases in the US.
Exercise and diet is the most effective treatment for type II
The EEOC has found that obese workers earn 2.5% less than
their normal weight co-workers. This penalty is larger for female
workers (5-6% less) than male workers (1% less).
A study by Cornell University found that overweight women
earn an average of 7% less than their co-workers.
Research review by Mark Roehling, a professor in the Department
of Management, Western Michigan University found wages of mildly
obese white women were 5.9 percent lower than their normal weight
counterparts; morbidly obese white women were 24.1 percent lower.
In addition, the wages of mildly obese white and black men were
actually higher than their normal weight counterparts. Men only
suffered wage penalties at the very highest weight levels. Overweight
individuals were often stereotyped as socially handicapped, emotionally
impaired, and perceived as possessing negative personality traits.
It should be noted that employers may have to pay more in
health insurance for obese workers. Weight discrimination is
illegal in Washington, DC.
- Perivascular fat
- Pericardial fat
- Subcutaneous fat
- Perirenal fat
muscles use approximately 90% of the calories you consume.
Americans spend more than $30 billion a year on weight control
programs and products.
Gram-for gram, fat cells exert the most evident deleterious
impact when they are located centrally (visceral). See Waist
Hip Ratio Calculator.
Some authorities suggest women should have their thyroid
levels checked every 3 to 5 years. Individuals with low thyroid
levels can gain fat due to their condition.
Moderate weight loss of 510% is sufficient to augment
The menopause is associated with an increase in abdominal
adiposity and increased bone mineral loss in women.
On an average, active individuals eat more calories than overweight
You are 60 times more likely to die from liposuction than
any other type of surgery.
Obesity cost companies 12 billion US dollars per year. CNN
Headline News (18 June 2003)
Fitness is more highly correlated with health than is body
An average overweight American walks about 2,000 steps per
day. The average non-overweight American walks about 6,000 steps.
Turmeric and cinnamon are two spices that may slightly decrease
Children eat 25-60% more when portion sizes are double (FitTV,
March 26, 2010)