SCIENCE

FOOD ENERGY

Food energy is energy that animals (including humans) derive from their food, through the process

of cellular respiration, the process of joining oxygen with the molecules of food or of reorganizing 

the atoms within the molecules for anaerobic respiration. Food as we know provides us energy to

do work. So, it is important to have a healthy diet so that we can live healthily.

• COMPONENTS OF FOOD

Food component	Energy value
	kJ/g	kcal/g
Fat		38.9	9
Ethanol (drinking alcohol)		29	7
Proteins		17.2	4
Carbohydrates		17.2	4
Organic acids		13	3
Polyols (sugar alcohols, sweeteners)		10	2.4
Fibres		8	2

Fats are a wide group of compounds that are generally soluble in organic 

solvents and generally insoluble in water. Although the words "oils", "fats", 

and "lipids" are all used to refer to fats, in reality, fat is a subset of lipid.

"Oils" is usually to refer to fats that 

are liquids at normal room 

temperature, while "fats" is usually 

used to refer to fats that are solids 

at normal room temperature.

Ethanol is a volatile, flammable, colorless liquid 

with the structural formula CH3CH2OH. It is commonly referred 

to simply as alcohol or spirits. Ethanol is the principal type of 

alcohol found in alcoholic beverages, produced by the 

fermentation of sugars by yeasts. It can cause alcohol intoxication 

when consumed to excess. It is used in thermometers, as a 

solvent, as an antiseptic and as a fuel.

                                                                             

                        

                                                                      Proteins are essential 

nutrients for the human body. They are one of

the building blocks of body tissue, and can also

serve as a fuel source. As a fuel, proteins

contain 4 kcal per gram, just like carbohydrates

and unlike lipids, which contain 9 kcal per

gram. The most important aspect and defining

characteristic of protein from a nutritional standpoint is its amino acid composition.


Carbohydrate is a large biological molecule or macro-molecule      

 

consisting of carbon (C), hydrogen (H), and

oxygen (O) atoms, usually with a hydrogen:

oxygen atom ratio of 2:1. Some exceptions

exist; for example, deoxyribose, a sugar

component of DNA, has the empirical formula

C5H10O4. Carbohydrates are technically hydrates of carbon; structurally it is more accurate to

view them as polyhydroxe aldehydes and ketones.


An organic acid is an organic compound with acidic properties. The

relative stability of the conjugate base of the acid determines its acidity.

Other groups can also confer acidity, usually weakly: the thiol group –

SH, the enol group, and the phenol group. In biological systems, organic

compounds containing these groups are generally referred to as organic

acids.

                           Sugar alcohols, a class of 

polyols, are commonly added to foods because 

of  their lower caloric content than sugars and 

are often combined with high- intensity 

sweeteners. They are also added to chewing 

gum because they are not broken down by 

bacteria in the mouth or metabolized to acids, 

and thus do not contribute to tooth decay.

Dietary Fibres is found in cereals,

fruits and vegetables. Fibre is made

up of the indigestible parts or

compounds of plants, which pass

relatively unchanged through our

stomach and intestines. Fibre is

mainly carbs. The main role of fibre is

to keep the digestive system healthy.


WHAT IS A HEALTHY/BALANCED DIET? 

A balanced diet contains all the nutrients required by the human body in

adequate amounts. Healthy diet is moderation. Moderation means eating

only as much food as your body needs. You should feel satisfied at the end

of a meal, but not stuffed. It is about balance.


ENERGY IN YOUR FOOD

Kilojoules (food energy) are important for providing energy for your daily

activities and body function. Aim to balance the energy you consume

through foods with the energy you expend during the day.

The more active you are the more kilojoules of food energy you need. If

you are less active, your body needs fewer kilojoules of food energy to get

you through the day.

Balance Your Intake Throughout the Day

When you’re choosing foods and drinks, take a look at the DIG thumbnail

for energy. It can be easier to look at the % Daily Intake for energy and

compare to the % of energy recommended for that meal instead of thinking

about what you need for a whole day.

The Daily Intake Guide has been developed to show you how you can

distribute your energy intake over a day. It's based on 3 meals plus 2

smaller in-between meal snacks.

You can modify the guide to adapt it to your eating pattern on a given day.

For example if you have a large breakfast (greater than 20% of your daily

energy needs), you will need to modify (reduce) your intake amount for

mid-morning and afternoon snacks, lunch or dinner. Its common sense -

and now easier to understand with DIG!

Energy Variance

The percent Daily Intake values used in DIG are based on an average adult

diet of 8,700 kilojoules (kJ). Many people will require different amounts of

food energy at various stages of their lives and as their activity level varies.

A very active teenager, for example, will require more food energy than a

sedentary older person.


DAILY INTAKE

Recommendations in the United States are 2,700 and 2,100 kcal (11,300

and 8,800 kJ) for men and women (respectively) between 31 and 50, at a

physical activity level equivalent to walking about 2 to 5 km (1 1⁄2 to 3 mi)

per day at 5 to 6 km/h (3 to 4 mph) in addition to the light physical activity

associated with typical day-to-day life, with French guidance suggesting

roughly the same levels.

Children, those with sedentary lifestyles, and older people require

less energy; physically active people more. Instead there is a series of

recommendations for each age and gender group, although packaged food

and fast food outlet menu labels refer to the average daily energy intake of

8,700 kJ (2,100 kcal).

BMI SURVEY

The body mass index (BMI), or Quetelet index, is a measure of relative weight based on an individual's mass and height. Body Mass Index is a number calculated from a person's weight an height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health

BMI Calculation Range 

NAME	GENDER	NATIONALITY	HEIGH T	WEIGHT	BMI INDEX	REMARKS
Peter Talbot	Male	British	185cm	82kg	23.96BMI	Normal
Orla Kelly	Female	British	170cm	65kg	22.49BMI	Normal
Pamela Ng	Female	Chinese	167cm	57kg	20.44BMI	Normal
Darren Ng	Male	Chinese	181cm	74kg	22.59BMI	Normal
Aziza Shah	Female	Malay	164cm	94kg	34.95BMI	Heavily Overweight
Nur Hakim Shah	Male	Malay	168cm	80kg	28.34BMI	Overweight
S.Madhav	Male	Indian	170cm	75kg	24.95BMI	Overweight
Jamuna.M	Female	Indian	166cm	59kg	21.41BMI	Normal

BMI OF LESS THAN 18.5KG/M2

A BMI of less than 18.5 indicates that you are underweight, so you may need to put on some 

weight. You are recommended to ask your Doctor or a dietician for advice.

BMI OF 18.5 - 25KG/M2

A BMI of 18.5 - 25 indicates that you are at a healthy weight for your

height. By maintaining a healthy weight, you lower your risk of developing 

serious health problems.

BMI OF 25 - 30KG/M2

A BMI of 25 - 30 indicates that you are slightly overweight. You may be advised to lose some

weight for health reasons. You are recommended to talk to your Doctor or a dietician for 

advice.

BMI OF OVER 30KG/M2

A BMI of over 30 indicates that you are heavily overweight. Your health may be at risk if you do 

not lose weight. You are recommended to talk to your Doctor or a 

dietician for advice.

Food Adulteration – Adulterants & Test for Adulterants

What are Adulterants?

An adulterant is a substance found within other substances (e.g. food, 

beverages, fuels), although not allowed for legal or other reasons. The 

addition of adulterants is called adulteration. An adulterant is distinct from, 

for example, permitted food additives.

Food Adulteration:-

As we got to know about Adulteration above, we can easily understand 

that food adulteration is adding of the substance that is not allowed .An Adulterant is used 

either to enhance the look, taste, smell or others in the particular food.

Adulterants-

Adulterants are the substances that are being 

added to the substance to enhance its properties.

Common Adulterants:-

• Roasted chicory Roots-

Coffee

• Diethylene glycol-Wines

• Water-Milk and other Emulsions 

• High fructose corn syrup or cane sugar- Honey

• Water or brine injected into chicken, pork, or other meats to increase 

their weight.

• Sugar- Chalk Powder.

Effects of Adulteration:-

Deliberate addition of toxic adulterants to food or other products for human consumption is poisoning. Food adulteration can cause immediate effect on human health. Diarrhea, dysentery, vomiting are such type of effects. Tamarind and date seed powder mixed with coffee powder can cause diarrhea. Adulteration on bakery items and dairy products may have tremendous effects on a child’s health. Improperly processed milk and canned meat may cause food poisoning and abdominal pain. Vegetables and fish mixed with formalin and other type of chemicals which are used to keep the food fresh are injurious to health. Unhygienic meat and meat products can cause food infection usually with fever and chills.

TESTS FOR ADULTERATION

• Metanil Yellow is a synthetic dye which is not permitted to use as a 

food colour. However it extensively used to give yellow colour to dal 

and turmeric. It is toxic in nature and has adverse effects on human 

body (Liver, Intestine and brain).Presence of metanil yellow can be 

tested in by dal 

adding few drops of   Hydrochloric Acid to a test sample .If the solution turns pink or

magneta in colour, it indicates presence of metanil yellow.

• Wheat, Rice and other cereals are adulterated with seeds, dust, 

stones and other inedible particles. These can be visually examined 

and be removed if possible.

• Parched rice is commonly adulterated with Urea. For the test of urea, 

we have to mix it thoroughly with water in a test tube. After filtering 

the water contents we have to mix powdered soya bean or arhar to 

it. Later we have to dip a red litmus paper to it. The red litmus paper 

turns blue. This proves the presence of Urea in the Parched Rice.

CONCLUSION

Food choices, eating behaviours and resulting nutritional health 

are influenced by a number of complex and inter-related individual, 

collective and policy-related determinants. A growing body of 

research is supporting the relationship between food preparation 

and cooking skills and food choices of children and adolescents 

within the family context. Several technological, food system-

related and broader shifts within the social, economic, physical and 

cultural environments have been identified as factors influencing the 

culture of cooking and food preparation within the home or domestic 

environment, including the following:

• increased availability of food commodities (basic/raw and processed);

• improved and advanced technology for food storage, preparation 

and cooking; resulting in changes in the level of knowledge and skill 

required to cook;

• time and financial demands/ realities related to labour market 

participation;

• shifting family priorities and values; and

• decreased opportunities for cooking and food preparation skill 

acquisition both within the home and public education environments.

The information presented within this synthesis indicates that despite noted 

limitations in surveillance and intervention-related data, concerns related to 

a transition in cooking and food preparation skills and the potential impact 

on food choice, health, BMI and adulteration of food.