energy and we equate the calorie content to certain amounts of food ○ You’re burning food components with their release of calories which can be measured by: ■ Placing people in a room that is thermally insulated from the outside, have them do some kind of activity and measure the temperature change in the room (temp. Change comes from the energy that is being expended from doing that activity) ■ Measuring the amount of oxygen that is inhaled and the amount of carbon dioxide that is exhaled because that is proportional to the “burning of calories” because any combustion process requires the combination of the food component with oxygen to release carbon dioxide and water so we can measure the intake of oxygen and the exhaled amount of CO2
CHEM 181 ● To burn calories with exercise is very difficult; 500 calories burned is 1 hour of bicycling or under an hour of running at 10 mph ● Our body is always functioning and thus, we are always expending energy ● BMR is usually 1500-1700 calories per day ● Women need roughly 1800 calories and men need 2200 calories Video 4: ● BMR is the amount of energy that your body expends just to stay alive ○ Less in women than in men ● Humans are biochemically individual ● We don't use up the same amount of energy to do the same things; the same way that car doesn’t use the same amount of energy to move the same distance ● Some people have more efficient metabolism and therefore require fewer calories to keep their body functioning ● There are different biochemistry that are involved, and that requires different amounts of energy expenditure ● Low-carbohydrate diets work – but work far better for some people than for other ● People with metabolic syndrome do better on a low carbohydrate diet than others ● Metabolic syndrome occurs when: ○ The waste measurement exceeds 100 cm ○ Triglycerides above 1.7 Mmol/L ○ HDL under 1 Mmol/L ○ Blood pressure is greater than 130 systolic and greater than 85 diastolic ■ High BP in general, the systolic is above 130 and diastolic is above 85 ○ Blood glucose is greater than 6.1 Mmol/L ● Why do we have metabolic syndrome? ○ Part of it is genetic ● Is obesity genetics? ○ Native Americans, known as the Pima (some live in the United States and some live in Mexico) ■ A very, very large percentage of Pima who live in the United States are grossly overweight ■ The Pima who live in Mexico don’t tend to be as overweight compared to those of the US as they have a different lifestyle, they eat more vegetables, fewer fast foods, etc.
CHEM 181 ● There is a genetic propensity for overweight but in order to bring that out, you also have to have a poor diet ● Brown fat – fat that is brown when placed under a microscope ○ They are more adept at converting their food components – the carbohydrates, the fats; which means they can more efficiently burn those components and release energy than our other fat cells ○
- Spring '11