Recently some students requested that I help them answer a question on preparing a diet plan for a 30 year old pregnant woman.

In this tutorial I will provide general guidance on how to prepare a diet plan, using the example of a pregnant woman.

Disclaimer: The principles and Recommended Dietary Allowances (RDAs) mentioned are appropriate for the Indian setting only.

Tutorial

There are four elements in a diet prescription

1. Principles of Balanced Diet
2. Calculation of weight/volume
3. Food chart
4. Meal plan/ menu (optional in a theory examination)

The first step in any diet prescription is the computation of requirements for total calories and total proteins.

In order to do this, refer to the Summary of Recommended Dietary Allowances (RDA) for energy, protein, fat and minerals for Indians 2010 (Table 29 on page 636 of Park, 23^rd edition).

If the subject is a pregnant woman, one must determine the activity level, as the calorie requirements vary by activity level.

A housewife is considered to be a moderate worker.

Assuming the pregnant woman is a housewife, and weighs 55kg, the total calorie requirement would be:

Calorie requirement for woman engaged in moderate work:           2230 calories plus

Calorie requirement for a pregnant woman:                                        350   calories

Total calorie requirement:                                                                       2580 calories per day

Similarly, from the table, the total protein requirement for a pregnant woman is 78 grams per day

 

All subsequent calculations will be based on the above two values (total calorie and total protein requirement).

A. Principles of a balanced diet

1. Cereals: 60-70% of total calories should come from cereals

100 g cereals yield 350 Kcals energy and 10 g of Cereal Protein

2. Pulses: The ratio of cereal protein to pulse protein should be 5:1

100 g pulses yield 350 Kcals energy and 20 g of Pulse Protein

3. Fats: Should not be >10% of total calories

1 g of fat yields 9 Kcals energy and no protein

4. Refined sugar: Should not exceed 5% of total calories

1 g of refined sugar yields 4 Kcals energy and no protein

5. Milk:

100 ml milk yields 65 Kcals energy and 3.2 g Milk Protein

6. Boiled egg:

1 boiled egg yields 80 Kcals energy and 6 g of protein

7. Green Leafy Vegetables (GLV):

100 g of GLV yields 25 Kilocalories

B. Calculation

1. Cereals:

The total calorie requirement is 2580 Kilo calories, so calories from cereals should be 70% of 2580à 1806 Kcals.

100 g of cereals yield 350 Kcals, so the amount of cereals required to provide 1806 Kcals is (1806/350)*100 = 516 g.

516 g cereals will provide 51.6 g cereal protein

2. Pulses:

As the total proteins obtained from cereals is 51.6 g, pulse proteins should be: 51.6/5 = 10.32 g (or 10 g).

Since 100 g of pulses yield 20 g of pulse protein, the amount of pulses required to provide 10 g protein would be: (100/20)*10= 50 g.

50 g pulses will yield (350/2)= 175 Kilocalories energy

3. Fat:

The total calories required are 2580, so the total calories from fat should not exceed 258. The total grams of fat permissible would therefore be 258/9 = 28.6 g (29 g).

4. Refined sugar:

The total calories required are 2580, so the total calories from refined sugar should not exceed 129 calories. As one gram of carbohydrate yields 4 kilocalories, the total grams of refined sugar permissible would be 129/4= 32.25 grams.

Note: The WHO recommends a maximum of 25 grams of free sugars per day for adults.

5. Milk:

On average, a person may consume 2 cups (400 ml) of milk in a day.

This volume would yield 4*65= 260 kilocalories energy and 12.8 g of milk protein

6. Boiled egg:

The consumption of one boiled egg would yield 80 kilocalories energy and 6 grams protein

7. Green Leafy Vegetables:

As the subject is a pregnant woman, she would need to consume at least 100 grams of GLV to meet the dietary iron requirements.

This would yield 25 kilocalories and no proteins

C. Food Chart

S. No.	Food item	Amount (vol/wt)	Energy (Kcal)	Protein (g)
1.	Cereals	516 g	1806	51.6
2.	Pulses	50 g	175	10
3.	Fat	28.6 g	258	—
4.	Refined sugar	32.25 g	129	—
5.	GLV	100 g	25	—
6.	Milk	400 ml	260	12.8
7.	Boiled egg	60 g (1 egg)	80	6
	Total		2733	80.4

From the table, it is seen that although the protein requirements are satisfied, the calorie requirements are excess by 153 kilo calories.

To overcome this excess, one could decrease the amount of refined sugar to 25 g. This will decrease the calorie intake by 29 kilo calories without altering the protein value.

Additionally, fat consumption may also be reduced to 20 g- this will decrease an additional 78 kilo calories.

S. No.	Food item	Amount (vol/wt)	Energy (Kcal)	Protein (g)
1.	Cereals	516 g	1806	51.6
2.	Pulses	50 g	175	10
3.	Fat	20 g	180	—
4.	Refined sugar	25 g	100	—
5.	GLV	100 g	25	—
6.	Milk	400 ml	260	12.8
7.	Boiled egg	60 g (1 egg)	80	12
	Total		2626	86.4

The revised food chart results in an excess of 46 kilo calories, which is acceptable.

Note: The preparation of a menu (meal plan) is optional.

The same approach could be used to prepare a diet plan for other subjects.

Note: The most important part is the computation of total calorie and protein requirement. If this is wrong, all elements except the ‘principles of a balanced diet’ will be wrong as well.

Further reading:

Essentials of Community Medicine Practicals by DK Mahabalaraju