Food & Nutrition Test #2

Energy Sources

Carbohydrates (4 cal/g), Proteins (4 cal/g), Fats (9 cal/g)

Calculating Calories

Multiply the number calories from the energy (carbs, protein and fats) by the number of grams on nutrition facts. Then add all the sums together

Nutrient Density

Ratio of nutrients to calories in food; Nutrient dense - rich in nutrients relative to calories; Nutrient poor - low nutritional value compared to calories

Energy Balance

Intake and output of calories; Negative energy balance - consuming fewer calories than burned; Positive energy balance - consuming more calories than burned

How does the body use energy?

• BMR (Basal Metabolic Energy)

• Physical Activity

• Food processing

BMR (Basal Metabolic Rate)

Calculation for energy expenditure at rest; BMR = weight (lbs) x 0.4 x 24

Sedentary

Very little physical activity e.g., sit at a desk all day

Low Active

Moderate activity everyday e.g., walking to the bus

Active

Some physical activity everyday - at least 2.5 hours per week e.g., exercising, walking home, gym class

What is 1 pound of Body Weight?

1 pound of body weight is equivalent to 3,500 kcal (kilocalories)

Digestion

Process of breaking down food into simpler substances for cell use; Mechanical digestion - physical breakdown; Chemical digestion - breakdown with acids and enzymes

Mechanical (Digestion)

Happens as food is crushing and churned ex. chewing

Chemical (Digestion)

Food is mixed with powerful acids and enzymes (a type of protein produced by cells that cause specific chemical reactions)

GI Tract

Muscular tube from mouth to anus; Sections include mouth, esophagus, stomach, small intestine, large intestine

Another word for chewing

Mastications

Salivary Amylase

Helps break down the starches in food (happens in the mouth)

The Esophagus

10 inches long; as you swallow, food passes from the mouth to the stomach through this.

Peristalsis

Squeezing actions by the muscles in the esophagus, helps move food through the tube.

The Stomach

Protein begins here - when you eat, the stomach produces gastric juices to prepare for digestion.

Gastric Juices

Contain hydrochloric acid, digestive enzymes and mucus

Chyme

The mixture of gastric juices

Mucus

A thick fluid that helps soften and lubricate food. Helps protect stomach from acidic juices

Pepsin

The major gastric enzyme that begins to chemically break down protein

3 Sections of the small intestine

• Duodenum (12 inches long)

• Jejunum (4 feet long)

• Ileum (5 feet long)

Organs associated with the small intestine

• Pancreas

• Liver

• The Gallbladder

Pancreas

This organ secretes bicarbonate, which neutralizes hydrochloric acid coming from the stomach with the partially digested food. Also produces digestive enzymes that break down proteins, fats, and carbohydrates

Another word for ‘Protein’

Proteases

Another word for ‘Fat’

Lipases

Another word for ‘Carbohydrates’

Saccharidases

Liver

This organ produces digestive juice called bile which aids in fat digestion helps disperse fat in water-based digestive fluids

The Gallbladder

This organ stores bile until it is needed for digestive purposes

The Large Intestine (aka Colon)

Little digestion occurs here. Main job is to reabsorb water (chyme is very liquid when it enters the colon — stays for 1-3 days before elimination)

Feces

Solid wastes includes mucus, bile pigments, fibre, sloughed off cells from lining of the large intestine, and water

Rectum

End of large intestine

Anal Sphincter

Anus

BMI (Body Mass Index)

Measure of body fat based on weight and height; Healthy range:19-24.9; Formula: BMI = weight ÷ (height in inches)² x 705

What is the recommended weight loss range?

1-2 lbs per day

Calorie deficit

When your sum is more than your input

Calorie excess

When your sum is less than your input