World of Chem: Food February 28 Weight Control
Lewis Carroll best known for writing Alice in Wonderland also wrote The Walrus
and The Carpenter. Makes a reference to weight in it. Back in 1800s.
Epidemic of obesity in North America.
Diabetes: used to be juvenile and onset but now some adult diabetes are seen in
Manuel Uribe 550 kg record for heaviest man alive
o Now about 500 lbs
Average weight for men in North America
o In 1960 166 lbs
o In 2002 191 lbs
Average weight for women in North America
o In 1960 140 lbs
o In 2002 164 lbs
A medical problem just like cancer, heart disease, etc. The cure rate for obesity is less
than the cure rate for cancers. 1 in 20 obese people succeed in keeping their weight off.
Hippocrates confronted the problem: those desiring to lose weight should perform hard
work before food. They should take their meals after exertion and while still panting from
fatigue. They should, moreover, eat only once a day and take no baths and sleep on a hard
bed and walk naked as long as possible.
Fat-free diet; fat blocker diet (foods are supplemented to block absorption of fat); miracle
herbs; fat burner (chromium picolinate); cellulite dissolvers
o Cellulite is excess fat in the wrong place the back of the thighs mostly
Acu-stop 2000 is a pressure device that you put in your ear that supposedly curbs hunger
Patches, cabbage soup diet, mustard diet all non-sense. Low-carb diets, exemplified by
Dr. Robert Atkins (Atkins diet), high carb diets (Dean Ornish), Dr. Phil diets, naturopaths
diets, former accountants write diets, supplements, etc.
The imagination diet based on study published in Science Journal
o Imagining eating foods
o Would you eat less of the food that you imagined when you got the actual food
o Study showed that yes. But hasnt been replicated yet.
Obesity is a risk factor for heart disease, stroke, hypertension, cancer, diabetes.
o Diabetes: pancreas doesnt have enough insulin, glucose transformed into fat.
o Life expectancy for an obese person less than an average person.
Fast foods: high in calories, sugar, and salt (which leads to high blood pressure)
Caloric intake has been going up steadily in North America
o More desserts
o The biggest single problem is the consumption of soft drinks and their size. World of Chem: Food February 28 Weight Control
Sugar is one of the major problems in obesity; a disaccharide sucrose made from
glucose and fructose.
o Broken down in the body into glucose and fructose and absorbed into the
bloodstream; fructose eventually converted to glucose. Blood sugar = amount of
o Fructose levels after metabolism can lead to weight gain more than glucose.
o Not all carbohydrates behave the same way biochemically
o Glucose and fructose: same energy released in calorimeter. But do not act the
same way in the body!
o Our consumption of fructose has increased very dramatically over the past
o Increase in high fructose corn syrup
o Dr. Robert Lustig: theory that fructose does not blunt the appetite the same way;
lectin curbs the appetite and is not released by fructose.
Controversial not universally accepted
But more evidence that high consumption of HFCS is partially the cause
o Obesigens increase the appetite men with abdominal obesity, insulin resistance,
or both were more likely to have high concentration of phthalate metabolites (an
example of an obesigen) in their urine.
o Obesity in the stomach area is worse than elsewhere on the body the fat is
metabolically more active there. Triglycerides are loaded more readily than other
areas. Men with more beer belly are more prone to heart disease.
Beer belly: independent risk factor for stroke and heart disease
BMI = weight in kg / height in m 2
o Possible to have a high BMI and not be obese wrestlers with high muscle mass
o BMI vs. waist to hip ratio is a better indicator
o The amount of energy needed to raise the temperature of 1 g of water by 1 degree
o 1 food calorie = 1000 small calories
o Used to measure energy expenditure
o Your weight is determined by the calories in and the calories out.
o Expend more calories than taken in to lose weight
o Calorimeter: notion introduced by Wilbur Olin Atwater burned foods in
calorimeter and determined their calorie content
But some things in food are not used in the body and are excreted, so
correction was made by analysing urea in urine and nutrients of the food.
Metabolisable energy describes energy content of foodWorld of Chem: Food February 28 Weight Control
o The amount of energy that can be made available from that
o Underestimates energy needed to digest protein and soluble
fiber; thus only an approximation.
Net metabolisable energy: how much of the food is available to be
used as energy
o Lasagna: 250 g; 400 calories in calorimeter but really 367
o Carrots cooked and raw have different energies
Cooked have been already broken down
o Meat different steaks have some pre-digestion
Orange juice (1 cup) 108 calories
Fudge (1 square) 155 calories
Dynamite (1 gram) 155 calories
Metabolism: the energy consumption by biochemical processes (that you do not have
o Basal metabolic rate: we all have one. The energy you spend while doing nothing
and having no nutritional intake. Does not take into account exercise, etc.
o Activities require energy: