Energy Balance

Understand the trend in physical activity recommendations since 1988. Have they gotten more specific or more generalized?

1988 Surgeon General's Report on Nutrition and Health • At least 20 min, 3 X /wk 1995 Dietary Guidelines for Americans • 30 min/d, preferably 7 days/wk 1998 Canada's Physical Activity Guide to Healthy Active Living • 60 min/d of "light" exercise, or • 30-60 min of "moderate" exercise 4+ days/wk, or • 20-30 min of "vigorous" exercise 4+ days/wk 2005- 60 min/day of moderate- intensity PA

What is BEE and BMR

BEE refers to Basal Energy Expenditure and BMR is Basal metabolic rate. BMR: energy needed to sustain metabolic activities of cells and tissues, plus energy needed for circulations, respirations, an GI and Renal functions . Measuring BMR over 24hr period= BEE

What is the difference between BMR and RMR?

Basal Metabolic Rate (BMR) = energy expenditure while awake, after an overnight fast, supine, motionless - Basal energy expenditure (BEE) is BMR extrapolated to 24 h - Measured under very strict conditions (clinically) • Resting Metabolic Rate (RMR) = energy expenditure while at rest - Resting energy expenditure (REE) is RMR extrapolated to 24 h (includes TEF) - Measured under less restrictive conditions RMR tends to be higher than BMR by ~3% due to other external factors like recent Physical Activity, stress, etc

Do the current recommendations call for more or less physical activity than the original recommendations?

Current recommendations call for more PA than the original recommendation. Given recent history for finding the daily recommendations for PA, there has been an increasing number/ time of M-I activities. The only difference between the current and original recommendations is that the DHHS comes in weekly whereas comes in per day. DHHS 150min/wk and IOM 60min/day

What factors contribute to energy expenditure?

Energy intake - energy expenditure; Energy intake includes Carbs, alcohol, protiens and fats whereas energy expenditure equals respiration, metabolism, circulation, proteins synthesis and physical work.

Be able to calculate EER (you will only have to RECOGNIZE and use the equation, you will NOT have to memorize the equation for EER, it will be on the exam, be sure to know the units).

Men: EER = 662 - (9.53 x Age(yrs)) + PA [(15.91 x Weight (kg)) + (539.6 x Height (m))] Women: EER = 354 - (6.91 x Age (yrs)) + PA [(9.36 x Weight (kg)) + (726 x Height (m))]

4. Know the equation for PAL and be able to use in a calculation (you will have to MEMORIZE the equation for PAL and be able to understand how it is used).

PAL (physical activity level) = TEE / BEE (TEE = thermic effect of food, BEE = basal energy expenditure)

All things being equal, how does gender influence basal energy expenditure?

Sex- hormones, body comp. Difference between sexes. BEE changes in different phases of menstrual cycles

What represents the biggest source of variability in total energy expenditure (TEE)

TEE(total Energy expenditure)= BEE(Basal energy expenditure- 60-70%) + TEF( thermic effect-10%)+PA (Physical Activity- 20-30%) So BEE is the biggest source of variability in TEE

What is TEF

TEF ( Thermic Effect of Food)- increase energy expenditure caused by food consumption. Digestion, transport, metabolism and storage. It varies by amount and amount eaten in food; proteins have a higher metabolic cost than carbs and fat due to the metabolism of AA.

6. Know all the factors that influence energy requirements. a. Which factor is most variable? b. Which factor is most negligible

a. weight and PA b. body composition and size physical activity level ( most variable) sex genetic race other (age/ state growth, physical environment)

What is used instead to give us a guideline for energy intake?

• Average dietary intake that is predicted to maintain energy balance in a healthy adult of a specific age, gender, weight, height and physical activity Calculating of EER for Adults • Different equations for men and women • Variables include age, height (m), weight (kg) and physical activity (PA) coefficients

Why isn't there an RDA for energy intake?

• By definition RDA is the amount that would meet the needs of 97-98% of the population • Any intake above what is required would result in weight gain, which puts people at risk of comorbidities.