Nutrition Science Total Energy Expenditure Quiz

Energy Balance & Weight Management

• The lecture focuses on energy balance and weight management.
• Recommended reading for this topic is Mahan, L.K., and Escott-Stump, S. Krause's Food and Nutrition Therapy, 12th edition, W.B. Saunders, 2008.
• The professor's contact information is provided.

Part I: Focus on Energy Balance

• This section focuses on the total metabolic rate (MR) or total energy expenditure (EE).
• Energy is needed for several functions.
• Activity thermogenesis (AT) accounts for 25-35% of physical activity.
• Non-exercise activity thermogenesis (NEAT) includes daily living activities.
• The thermic effect of food (TEF) ranges from 5-10% of the total energy expenditure.
• A significant portion (60-65%) of BMR is for basal energy expenditure (BEE).

Basal Energy Expenditure (BEE)/Basal Metabolic Rate (BMR)

• BMR is the minimum amount of energy needed for normal body functions.
• Respiration, circulation, turnover, and temperature regulation are key components.
• The liver, brain, heart, and kidneys consume about 60% of BEE.
• Measurements are taken in the morning after an overnight fast: 10 hrs after the last meal, drink, or smoke.
• BMR is very consistent (60-70% of TEE).
• Resting metabolic rate (RMR) is usually slightly higher (10-20%) than BMR (BEE).

Resting Energy Expenditure (REE)/Resting Metabolic Rate (RMR)

• Factors affecting REE/RMR include:
  • Body size (taller, thinner people tend to have a higher REE than shorter, wider people).
  • Body composition (higher fat-free mass [FFM] typically results in a higher REE).
  • Age (RMR is highest during puberty and decreases with aging).
  • Gender (women generally have a slightly lower RMR than men when compared at the same weight).
  • Hormonal status.
  • Stress.
  • Other factors like caffeine, nicotine, and alcohol.

Measuring Fat-Free Mass (FFM)

• Methods to measure FFM include:
  • Underwater weighing (hydrodensitometry).
  • Dual-energy X-ray absorptiometry (DEXA).
  • Air displacement plethysmography (BOD POD).
  • Skinfold anthropometry (SFA).
  • Bioelectrical impedance analysis (BIA).

Measuring the Thermic Effect of Food (TEF)

• TEF is the energy expenditure associated with food digestion, absorption, metabolism, and storage.
• TEF for protein and carbohydrates is higher than for fat (carbohydrates: 25%, fat: 4%).
• For practical purposes, TEF is estimated as 10% of total energy expenditure (TEE).

Measuring Activity-Related Energy Expenditure (TEE)

• To estimate (TEE) use the doubly labeled water (DLW) method for complete activity.
• Subtract the resting energy expenditure from the total energy expenditure values to get the activity components.
• TEE = REE (RMR) + AT + TEF.

Devices for Monitoring Physical Activities

• Examples of devices used to monitor physical activities.
• Caltrac Monitor, Heart Rate Monitor- Uni axial (vertical plane).

Estimating Energy Requirements Based on Questionnaires

• People often underestimate their food intake (10-45%).
• Underestimation increases with age and is more common in women and obese individuals.
• Certain foods like beer, chips, popcorn, pizza, pretzels, cookies, brownies, pancakes, waffles, cakes, pies, frozen dairy desserts, ready-to-eat cereals, and non-diet soft drinks are frequently underreported.

Estimated Energy Requirement (EER)

• EER is the average intake to maintain a healthy lifestyle.
• It takes into account age, gender, weight, height, and activity level.
• EER estimations are important for children, pregnant people, and breastfeeding women to cover the physiological energy needs.

Calculating/Predicting EER

• EER can be calculated with two parameters: Physical Activity Level (PAL) and physical activity coefficients (PA).
• PAL = TEE/BEE
• Physical activity levels (PALs) are used to estimate physical activity levels for sedentary people, low-active people, active people, and very active people (PA).
• Different PALs have different physical activity coefficients.

Body Mass Index (BMI)

• BMI is calculated as Weight/(Height)² (kg/m²).
• Categories of weight: Normal, Overweight, Obese, Severely Obese, Morbidly Obese.
• BMI values determine categories of weight.

Calculating Estimated Energy Requirement (EER) considering PA and BMI

• Formula to estimate EER for men (19 years and older; BMI 18.5–25 kg/m²).
• The calculation considers age, physical activity, weight, and height.

Overweight and obese Men (BMI ≥25 kg/m²)

• Formula used for calculating TEE for overweight and obese men (19 years and older; BMI ≥ 25 kg/m²).

Body Weight Components

• Body weight components, essential and storage fat, as well as fat-free mass (FFM).
• Lean body mass (LBM) is a critical component, consisting primarily of skeletal muscles, water, bone, and a small amount of essential fat.

Body Fat

• Essential vs. storage fat.
• Storage fat is primarily triglycerides and is considered expendable.

Fat Cell Development - Hypertrophy & Hyperplasia

• Adipose tissue may increase in size (hypertrophy) or number (hyperplasia).
• Hypertrophy encompasses a larger size of existing fat cells.

Regulation of Body Weight

• Regulation of body weight involves numerous factors: various neurochemicals, body fat stores, protein mass, and hormones.
• Short-term regulation manages food intake throughout the day.
• Long-term regulation balances the body's energy needs, depending on the amount of adipose stores.
• Glycemic index (GI) helps measure how quickly carbohydrate-containing foods raise blood glucose.

Commercial Diet Programs

• The effectiveness of commercial weight-loss programs is questionable.
• Controlled trials are needed to assess their effectiveness.

Natural Weight-Loss Aids

• The market for over-the-counter weight-loss supplements has exploded.
• Products that may be unproven effectively for weight loss have shown potential risks and hazards.

Drugs and Dietary Supplements

• Proof of safety and efficacy is needed for drugs; no such requirements are needed for dietary supplements.

Milestones in Food and Drug Safety

• History of food and drug safety regulation, including milestones like the Pure Food and Drug Act, the FDA establishment, the Food, Drug, and Cosmetic Act, and the Dietary Supplement Health and Education Act.
• These acts aimed to standardize safety and quality standards needed in the market and ensure that products are appropriately assessed.

Other sections:

• Included other information from the provided documents (like pharmacology and specific examples of weight-loss drugs and their functions).