1. CH. 17 Energy Balance and Temperature Regulation

2. Do We Have Enough Energy? Understand what energy is and what it is used for Know how much energy is actually used and how much we lose as heat Understand what metabolic rate and basal metabolic rate are a measure of Know the types of energy balances that exsist Understand what nutrients are and how we regulate nutrient intake

3. Energy Input – energy stored in the bonds of ingested food Output – the use of that energy – External work Energy expended during skeletal voluntary skeletal muscle contractions – Internal work All forms of biological expenditure that do not perform work outside of the body – Involuntary skeletal muscle contractions – All life sustaining activities that are always occurring

4. Energy Consumption How much energy do we actually use? Lose about 75% as heat Metabolic rate – Rate of energy use – Energy used/unit time – Expressed in calories, and kilocalories (Calories) – BMR – Basal metabolic rate Minimum waking rate of internal energy expenditure Influenced by thyroid hormone

5. Neutral Energy Balance Energy input = energy output Three states of energy balance – Neutral energy balance Amount of intake = to output – Body weight remains constant – Positive energy balance Amount of intake > output – Excess stored s adipose, weight increases – Negative energy balance Amount of intake < output – Body must use stored energy, weight decreases laali.kau.edu.sa

6. Nutritious and Delicious Nutrient – An ingested chemical that is used for growth, repair, and maintenance of the body – Two categories Macronutrients – Must consume in large quantities – Water, carbohydrates, lipids, and proteins Micronutrients – Small quantities needed – Minerals and vitamins Calories – Kcal – Measure of the capacity to do work

7. Metabolic States Absorptive state – Nutrients are being absorbed and my be used immediately to meet needs Postabsorptive state – Stomach and small intestines empty, energy needs met from stored fuel

8. Regulation of Appetite Short-term regulators – Ghrelin – produces sensation of hunger – Peptide YY (PYY) – sensation of satisfaction – CCK – sensory stimulus of vagus nerve (suppressor) Long-term regulators (adiposity signals) – Leptin – Insulin Arcuate nucleus of hypothalamus – NPY - stimulator – Melanocortin - suppressor

9. Psychosocial and Environmental Influences Eat out of habit Social custom Familial customs mindfully.org