No. 20. Caloric Needs of Different Groups and The Glycemic Index of Foods

Aim

To prepare an educational chart/poster on caloric intake for children and mothers and glycemic index of foods that are available locally.

Practical Significance

Calories serve as a measure of the energy released when food is broken down in the body. Maintaining a healthy weight relies on finding the right balance between the calories consumed and the calories burned. The glycemic index is a value assigned to foods based on how quickly and significantly they raise blood glucose levels. Understanding the glycemic index of foods is crucial for individuals who have diabetes, obesity, or heart disease. Pharmacists play an important role in health promotional activities focused on nutrition. In this practical, students will be able to explain the specific caloric needs of different groups, such as children, mothers, and individuals leading sedentary lifestyles. Moreover, they will emphasize the significance of the glycemic index in promoting healthy dietary habits.  

Theory:

Calorie

Calorie – A unit of energy in food. Every human being requires energy for normal functioning. Energy is obtained from the foods we consume, in the form of calories. Calories are a measuring unit of energy that is required by the human body to perform any function/activity. The amount of energy contained in food is expressed in calories. Energy (calories) is provided to the body by eating or drinking food. Then this energy is used as a fuel by the body to run various activities and functions. If a person is physically active, more calories are used up than the one who leads sedentary life. The commonly used measure of food calories refers to kilocalories (Kcal) or 1000 cal. It is advised that 45–65% of your calories come from carbohydrates, 10–35% from proteins and 20–35% from fat. An adequate amount of food (calorie) intake is needed for the body to function properly. Lack of food (calorie) intake can lead to lessened immunity, muscle atrophy, lethargy and sometimes organ failure. The calorie requirement of an individual depends on various factors as given below.

Factors affecting calorie requirements of individuals:

1. Age
2. Sex
3. Height
4. Weight
5. Basal metabolic rate
6. Level of physical activity

Age and gender influence basal metabolic rate and therefore, affects one’s caloric allowance. In general, male require more calories than females of the same age to maintain a healthy body weight and energy level. An active person requires more calories to remain fit and perform at the optimum level. If the calorie intake is less than adequate, the person might feel lethargic. If the calorie intake exceeds the recommended requirement, it might lead to obesity. Due to the growing awareness among the people about healthy eating habits, many people avoid eating high calorie foods to stay lean and thin. But some people exaggerate it.

Advantages of maintaining adequate calorie levels in the body:

1. Growth and development of the body
2. Proper functioning of body organs
3. Maintaining ideal body weight
4. Maintaining physiological process in the body
5. Building body immunity

Calorie requirement calculation

Basal Metabolic Rate (BMR) is equal to the amount of energy essential for the body to function if it were to rest for 24 hours. BMR is the minimum number of calories that your body requires for basal functions like digesting, breathing, and keeping the body temperature steady over a day. Determination of BMR is very easy; all you need to measure is your height and weight. The formula to calculate BMR of both sexes are as follows:

For Men:

BMR = 10 × Weight (kg) + 6.25 × Height (cm) – 5 × Age (years) + 5

For Women:

BMR = 10 × Weight (kg) + 6.25 × Height (cm) – 5 × Age (years) – 161

Harris Benedict Equation is a formula that uses Basal Metabolic Rate (BMR) and then applies a physical activity factor to determine total daily requirement of calorie / energy expenditure.

Calorie requirement = BMR × Your Physical activity factor.

Physical Activity type	Physical Activity Factor
Sedentary (little or no exercise)	1.2
Light exercise	1.375
Moderately active	1.55
Very active – hard exercise	1.725
Extra active – very hard exercise	1.9

Glycemic index

The glycemic index (GI) is a number from 0 to 100 assigned to a food, which represents the relative rise in the blood sugar/glucose level two hours after eating that food. GI is used to measure how much a specific food can affect blood glucose levels. Foods are grouped as low, medium, or high glycemic foods and ranked on a scale of 0–100 (Below Table). Foods with a high GI are rapidly digested and absorbed, causing a rapid rise in blood glucose. The higher the GI, the greater the effect on blood glucose levels. Foods with a low GI are digested and absorbed at a slower rate, and subsequently, cause a slower rise in blood glucose levels. These foods are rich in protein, fiber, and/or fat. Examples of Low GI foods: apples with a GI of 28, peanuts at 7 and Greek-style yogurt at 11 but a low GI doesn’t mean a food is high in all nutrients. One needs to eat healthy foods from all types of food groups. Dietary management according to GI is especially essential for fitness for people with diabetes or those over 35 years of age.

Classification of Foods based on GI value

Type of Food	GI rating	Physical Activity Factor
High GI	≥70	Rapid increase in blood glucose level
Medium GI	56-69	Moderate increase in blood glucose level
Low GI	≤ 55	Slow increase in blood glucose levels

The GI of a specific food depends mainly on the type and quantity of carbohydrate present in it; but also, is affected by the fat and protein content of the food, the amount of organic acids, the amount of entrapment of the carbohydrate molecules within the food. The variations in GI of specific foods are possible due to:

1. Ripeness: Riper fruits contain a higher amount of sugars, which increases their glycemic index (GI).
2. Processing: Whole grains have a lower glycemic index (GI) compared to their flour counterparts, as grinding breaks the grain’s protective coat and reduces its storage length.
3. Cooking methods: Overcooked food has a higher glycemic index (GI) because cooking breaks down its cellular structure, causing it to digest very quickly and leading to an increase in blood sugar levels.

Benefits of diet with low GI value

1. Improved weight loss: Lowering the glycemic load of the diet appears to be an effective method of promoting weight loss and improving lipid profiles and can be simply incorporated into a person’s lifestyle.
2. Reduced Cholesterol level: Following a low GI diet may help lower levels of both total and LDL (bad) cholesterol, both of which are risk factors for heart disease.
3. Increased blood glucose regulation: Low GI diet may reduce blood glucose level.
4. Improved athletic performance: Athletes may benefit from eating low-GI foods before exercise, as these foods will provide exogenous carbohydrates during exercise, which can help maintain blood glucose levels.

High-GI foods may be useful during lengthy exercise to promote carbohydrate usage and help maintain adequate blood glucose levels, as well as after exercise, to help promote muscle glycogen resynthesis.

Procedure:

Activity I

Write the information about chart on caloric intake as per locally available foods for child and mother.  (in a record book)

Activity II

Create a chart/poster containing information about glycemic index of the following: (in a record book and chart/poster)

1. 5 locally available foods.
2. 5 locally available fruits.
3. 5 locally available vegetables.
4. 5 Dairy products.
5. 5 Junk foods.

Calculations:

For Men:

BMR = 10 × Weight (kg) + 6.25 × Height (cm) – 5 × Age (years) + 5

_________________________Calories/ day

For Women:

BMR = 10 × Weight (kg) + 6.25 × Height (cm) – 5 × Age (years) – 161

_________________________Calories/ day

Calorie requirement = BMR × Your Physical activity factor.

Physical Activity type	Physical Activity Factor
Sedentary (little or no exercise)	1.2
Light exercise	1.375
Moderately active	1.55
Very active – hard exercise	1.725
Extra active – very hard exercise	1.9

Calculate for all physical activity factors.

Result

An educational chart/poster on caloric intake for children and mothers and glycemic index of foods that are available locally was prepared.

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