Energy values of foods

Foods are the main soucre of energy and it is important to understand the energy value of foods.

1. SUBMITTED TO:
Dr. Naveen
SUBMITTED BY:
Abhishek Thakur

2. What is
energy?
Energy: the capacity to do work, such as moving or
heating something.
Calorie: the unit used to measure energy
a kilocalorie is a unit of energy
commonly used to express energy value of food

3. Energy
How we generate Energy from Food
Energy In and Energy Out
Input = Food and Calories
Output = Metabolism (BMR) and Physical Activity
Balance
Weight Maintenance
Weight Increase
Weight Loss

4. The Nutrients in
Foods
Nutrients: substances obtained
from food and used in the body
to promote growth, maintenance,
and repair.
Essential nutrients: nutrients
that must be obtained from food
because the body cannot make
them for itself.
Nonessential nutrients:
nutrients that the body needs,
but is able to make in sufficient
quantities when needed; do not
need to be obtained from food.

5. Provide
Energy?
-Carbohydrate
-Protein
-Fat
-Vitamins
-Minerals
-Water
YES
YES
YES
NO
NO
NO
The energy-
yielding nutrients

7. Calorie Values
Calorie value of carbohydrate, fat, and protein…
If you know the number of grams of carbohydrate, fat, and protein in a
food, you can calculate the number of calories in it. For example, a deluxe
fast-food hamburger contains about 45 grams of carbohydrate, 39 grams
of fat and 27 grams of protein (see above).
Remember this
number…

8. Percentage of Total Energy Intake
The percentage of your total energy intake from carbohydrate, fat,
and protein can then be determined by dividing the number of
calories from each energy nutrient by the total calories, and then
multiplying the result by 100.

9. Components of Energy Output
We Need Energy for:
Basal Metabolism
BMR = Basal Metabolic Rate
Physical Activity
Metabolizing Food

10. Calories and Energy
Balance –
Calories IN = Calories OUTMaintain Weight
Calories IN > Calories OUTGAIN Weight
Calories IN < Calories OUTLOSE Weight
To maintain a desirable weight, energy
intakes should not exceed energy needs.

11. It’s all about Calorie Balance
If you eat more calories than your body uses,
they will be stored as fat
One pound of body fat is equal to 3,500 kcal
In theory, losing one pound requires a deficit of
3,500 Calories
Eating 500 fewer Calories per day - or
expending 500 more Calories - would result in
losing one pound per week

12. Input &
Output
Example
Intake:
3,400 kcal
Output:
3,005 kcal
IMBALANCE:
395 kcal
Eating Breakfast
20 min.
At the Gym
40 min.
Coffee Break
10 min.
Sitting in Class
180 min.
Walking to
Campus
20 min.
Dressing/
Washing
20 min.
Walking on
Campus
30 min.
Snack
10 min.
Lirary/Study
180 min. Eating Lunch
30 min.
Walking Home
20 min. Eating Dinner
30 min.
Check email
30 min. Driving to-from
Date
30 min.
Sleep 71/2
hours
Dancing
40 min.
Eating Snack
20 min
Hanging out
with Date
120 min
Emailing/Texting
Studying
120 min
Undress/Shower
30 min
650
50
50
100
270
210
25
150
250
25
395
700
75
200
280
100
75
1200
65
55
400
390
50
180
260
105
490
Walking to-from
Campus
30 min.
A day in the life…

13. Weight Management:
To maintain body weight in a healthy
range, balance calories from foods and
beverages with calories expended
To prevent gradual weight gain over
time, make small decreases in food and
beverage calories and increase
physical activity

14. Energy Expenditure:
Calorie expenditure depends on:
Weight of person
Type of activity:
○Length of activity
○Speed of activity
○Metabolic rate
From: Ainsworth, BE, et. al. 1993. Compendium of physical
activities: classification of energy costs of human physical
activities. Medicine and Science in Sports and Exercise. 25 (1):
71-80.

15. The ABCs of Eating for Health:
Adequacy:
getting all of the essential nutrients, fiber, and energy
(calories) in amounts sufficient to maintain health
Balance:
eating foods rich in one nutrient while not crowding out
foods that are rich in another nutrient
Calorie control:
control of energy consumption
Moderation:
no unwanted constituent in excess
Variety:
different foods, same purposes, different occasions

16. Contd..
Nutrient dense:
refers to a food that supplies large amounts of nutrients
relative to the number of calories it contains.
The higher the level of nutrients and the fewer the number
of calories, the more nutrient dense the food

18. Energy Balance:
Body weight is stable when energy
consumed is equal to energy expended.
When energy consumed is greater than
expended, weight increases.
When energy consumed is less than
expended, weight decreases.
One pound of body weight is equal to
3,500 kcalories.
© 2008 Thomson - Wadsworth

19. Energy Out: The kCalories the
Body Expends
Energy expenditure includes basal
metabolic activities, physical activity,
thermic effect of food and adaptive
thermogenesis.
These energy requirements differ from
person to person and are affected by
age, gender, weight, and height.
The intensity and duration of physical
activity also make a difference.
© 2008 Thomson - Wadsworth

20. © 2008 Thomson - Wadsworth

21. Energy Out: The kCalories the
Body Expends
Components of Energy Expenditure
Basal Metabolism (basal metabolic rate,
BMR)
○2/3 of energy expenditure
○Supports the basic processes of life
○Resting metabolic rate (RMR) is a measure of
energy slightly higher than BMR.
© 2008 Thomson - Wadsworth

22. Energy Out: The kCalories the
Body Expends
Components of Energy Expenditure
Basal Metabolism - Factors affecting BMR
○Aging slows BMR
○Height – the taller, the higher the BMR
○Growth increases BMR.
○Body composition (lean body mass increases BMR)
○Fever increases BMR.
○Stress increases BMR.
○Environmental temperature - both heat and cold raise
BMR
© 2008 Thomson - Wadsworth

23. Energy Out: The kCalories the
Body Expends
Components of Energy Expenditure
Basal Metabolism - Factors affecting BMR
○Fasting/starvation slows BMR.
○Malnutrition slows BMR.
○Hormones
Thyroid hormones can increase or decrease BMR.
Premenstrual hormones can increase BMR.
○Smoking increases BMR.
○Caffeine increases BMR.
○Sleep slows BMR.
© 2008 Thomson - Wadsworth

24. Energy Out: The kCalories the
Body Expends
Components of Energy Expenditure
Physical activity
○Most variable and changeable
○Voluntary
○It can be significant in weight loss and weight
gain.
○Duration, frequency and intensity influence
energy expenditure.
© 2008 Thomson - Wadsworth

25. Energy Out: The kCalories the
Body Expends
Components of Energy Expenditure
Thermic effect of food (TEF) is estimated at
10% of total energy intake and involves
digestion and absorption.
○Carbohydrate 5-10%
○Fat 0-5%
○Protein 20-30%
○Alcohol 15-20%
Adaptive thermogenesis is the adjustment in
energy expenditure related to environmental
changes.
© 2008 Thomson - Wadsworth

26. Energy Out: The kCalories the
Body Expends
Estimating energy requirements is affected by
many factors.
Gender – men generally have a higher BMR
Growth – BMR is high in people who are
growing
Age – BMR declines as lean body mass
decreases
Physical activity – Activities are clustered by
intensity and vary considerably
Body composition and body size – taller people
have more surface area and heavier people
have higher BMRs
© 2008 Thomson - Wadsworth

27. Body Weight, Body Composition,
and Health
Current weight standards use height and
weight data and do not take body
composition into consideration.
These may be misleading.
© 2008 Thomson - Wadsworth

28. Body Weight, Body Composition,
and Health
Defining Healthy Body Weight
Body mass index (BMI) measures relative
weight for height.
○Underweight is a BMI below 18.5.
○Overweight is a BMI above 25.
○Obese is a BMI above 30.
© 2008 Thomson - Wadsworth

29. Body Weight, Body Composition,
and Health
Body Fat and Its Distribution
Some People Need Less Body Fat
○Fat for fuel
○Fat for insulation and protection
○Fat to assist in nerve impulse transmissions
○Fat to support normal hormone activity
Some People Need More Body Fat
○Thresholds differ among individuals
○Thresholds differ for each function
© 2008 Thomson - Wadsworth

30. © 2008 Thomson - Wadsworth

31. Body Weight, Body Composition,
and Health
Body Fat and Its Distribution
Fat Distribution
○Intra-abdominal fat around abdominal organs
may be critical.
○Central obesity is excess fat around the trunk
of the body. It is also called abdominal fat or
upper-body fat.
○Associated with increased risks
© 2008 Thomson - Wadsworth

32. Body Weight, Body Composition,
and Health
Body Fat and Its Distribution
Waist Circumference
○Practical indicator of fat distribution and
abdominal fat
○≥ 35 is considered high risk for women.
○≥ 40 is considered high risk for men.
© 2008 Thomson - Wadsworth

33. Body Weight, Body Composition,
and Health
Body Fat and Its Distribution
Other Measures of Body Composition
○Monitoring changes over time is important.
○Fatfold measures
○Hydrodensitometry
○Bioelectrical impedance
○Air displacement plethysmography
○Dual energy X-ray absorptiometry (DEXA)
© 2008 Thomson - Wadsworth

34. Body Weight, Body Composition,
and Health
Health Risks Associated with Body Weight and
Body Fat
An appropriate weight for an individual depends
on many factors which include body fat
distribution, health history and current state of
health.
Health Risks of Underweight
○Cannot handle medical stresses
○Menstrual irregularities and infertility
○Pregnancy problems
○Osteoporosis and bone fractures
© 2008 Thomson - Wadsworth

35. © 2008 Thomson - Wadsworth

36. Body Weight, Body Composition,
and Health
Health Risks
Associated with
Body Weight and
Body Fat
Health Risks of
Overweight
○Diabetes
○Hypertension
○Cardiovascular
disease
○Sleep apnea
○Osteoarthritis
○Some cancers
○Gallbladder disease
○Kidney disease
○Respiratory problems
– Pickwickian
syndrome
○Complications in
pregnancy and
surgery
© 2008 Thomson - Wadsworth

37. Body Weight, Body Composition,
and Health
Health Risks Associated with Body
Weight and Body Fat
Cardiovascular disease and obesity have a
strong relationship.
Diabetes and obesity have a strong
relationship.
○Insulin resistance and obesity have a strong
relationship.
© 2008 Thomson - Wadsworth

38. Body Weight, Body Composition,
and Health
Health Risks Associated with Body
Weight and Body Fat
Inflammation and the Metabolic Syndrome
○High blood pressure
○High blood glucose
○High blood triglycerides
○Low HDL cholesterol
○High waist circumference
© 2008 Thomson - Wadsworth

39. Body Weight, Body Composition,
and Health
Health Risks Associated with Body
Weight and Body Fat
Cancer risk increases with weight gain but
the relationship is unclear.
Fit and Fat versus Sedentary and Slim
○Healthy weight is important.
○Cardiorespiratory fitness is important.
© 2008 Thomson - Wadsworth

40. Eating Disorders
Many individuals, including young females,
suffer from eating disorders.
These include anorexia nervosa, bulimia
nervosa and binge-eating disorders.
The causes include a combination of
sociocultural, psychological, and perhaps
neurochemical factors.
Athletes are among the most likely group to
develop eating disorders.
© 2008 Thomson - Wadsworth

41. © 2008 Thomson - Wadsworth

42. THANK YOUTHANK YOU