Alcohol, Digestion, Energy Balance NTR 300 – Fundamentals Dr. Lorna Shepherd

Alcohol/Ethanol Consumed by ~60% of Americans Provides 3% of total energy intake 7kcal/gm Is a narcotic Reduces sensation, consciousness, central nervous system depressant

Sources Beer 5-11% Wine 5-14% Distilled spirits >22% Liquors Alcohol listed as “proof” which is double the alcohol content

A standard drink 15gm of alcohol 12oz beer 5oz wine 10oz wine cooler 1.5oz hard liquor

Moderate ETOH Consumption One drink daily for female Two drinks daily for males Does not require digestion Absorbed by simple diffusion Easily crosses cell membranes but does damage as it passes through

Metabolism of ETOH The cells of the GI tract metabolize % of the alcohol ingested The remainder is metabolized by the liver Not stored so takes priority in metabolization alcohol –> acetaldehyde –>acetyl Co-A

Potential Benefit of ETOH Moderate intake reduces risk of CVD Reduces LDL

High Alcohol intake With high ETOH intake the liver uses an alternate path (microsomal ethanol oxidizing system) MEOS More efficient Requires energy Increases tolerance Decrease ability to metabolize drugs

Health Effects of Alcohol Increase blood pressure and stroke Cirrhosis of liver Poor food intake Deficiency of B vitamins Niacin needed for alcohol metabolism Thiamin absorption affected Increased excretion of B6 May impair absorption of B12

Excessive Intake of ETOH Increased risk of Brain damage Oral and esophageal CA Breast CA Irritation of stomach lining Cirrhosis of liver Pancreatitis and pancreatic CA Impaired nutrient use Fetal alcohol syndrome

Fetal Alcohol Syndrome 1 in every 1000 First 12 – 16 weeks of fetal development most critical Fetal alcohol effect Short attention span Learning and behavioral difficulties hyperactivity

Actual Picture

Energy Metabolism Substrates Converted to Acetyl CoA and enter to Kreb’s cycle to produce energy Carbohydrates – 4kcal/gm Lipids – 9kcal/gm Proteins – 4kcal/gm Alcohol – 7 Kcal/gm

Metabolism

Ketone Bodies Produced by liver and (kidney) The brain uses it during periods of fasting when glucose is not available

Hormones involved in Energy Metabolism (Regulation) Insulin Glucagon Thyroid

Energy Balance

Basal Metabolic Rate (BMR) The minimum amount of energy needed when resting and fasting

Factors that affect BMR Muscle mass Body surface area Gender body temperature Thyroid hormone Stages of growth Stimulants Sedatives

Methods of Calculating Energy Requirement Predictive equations Harris-Benedict Simple method – 30-35kcal/kg

Harris Benedict Equation Male 66.5+(13.8xWt)+(5xHt)-(6.8xage) Females (9.6xWt)+(1.9xHt)-(4.7xage) Activity factor Sedentary – 1.0 Low – 1.1 Active Very active – 1.46

BMI Formula

Body Mass Index Interpretation of BMI: Under weight <18.5 Healthy – 18.5 to 24.9 Over weight – 25 to 29.9 Obese - >30

Ideal Body Weight (IBW) Hamwi Males First 5’ = 106# 6# for each additional inch Females First 5’ = 100# 5# for each additional inch

Other: measurement of body fat Skin fold thickness Bioelectric impedance Underwater weighing

Percentage Body Fat Description Women Men Essential fat 10-13% 2-5% Athletes 14–20% 6-13% Fitness 21–24% 14-17% Average 25–31% 18–24% Obese 32%+ 25%+

Health risk associated with obesity Increase risk for Diabetes Hypertension Some types of Cancers Colon, uterus, prostate CardioVascular Disease Joint disorders/arthritis Sleep apnea

Distribution of fat

Waist Circumference Males 40 inches (102cm) or less Females 35 inches (88cm) or less

Weight Reduction Interventions Reduce caloric consumption Diet Behavior modification Surgery Increase energy expenditure 3500kcal = 1 pound (#) 500kcal/day

Eating disorders Anorexia nervosa Refusal to maintain weight at or above normal Intense fear of gaining weight Disturbance in perception of body image or denial of seriousness of low body weight Amenorrhea

Anorexia symptoms Low body weight Lower body temperature Slower metabolic rate Anemia Rough scaly skin Loss of hair Low WBC count Lanugo

Bulimia Nervosa Recurrent binge eating episodes Inappropriate compensatory behavior to prevent weight gain Purging – vomiting or abuse of laxatives Undue influence of body weight or shape on self-evaluation Symptom Erosion of teeth enamel, GI problems