NCERT Textbook: Food, Nutrition, Health and Fitness | Home Science for Class 11 - Humanities/Arts PDF Download

 Page 1


Human Ecology and Family Sciences – Part I
28
3
Food, Nutrition, 
Health and 
Fitness
3.1 Introduction 
The	 onset	 of	 adolescence	 brings	 with 	 it 	 many 	 pr ofound 	 changes.	 The	 gr owth	
rate 	 speeds 	 up 	 dramatically. 	 This	 gr owth 	 spurt	 occurs	 due	 to	 the	 activity	
of 	 hor mones	 that	 af fect 	 every	 or gan	 of	 the	 body	 and 	 this 	 makes	 healthy 	
eating	 very 	 important.	 The	 nutrient 	 needs 	 rise	 thr oughout 	 childhood,	 peak	
in adolescence and then level off or even diminish as the teenager becomes 
an 	 adult.	 The 	 saying	 ‘‘Y ou 	 ar e	 what	 you	 eat” 	 seems	 to 	 be 	 pr oven 	 true.	 W e	
eat 	 dif fer ent	 kinds 	 of	 food	 such	 as	dal, chapatti, bread, rice, vegetables, 
milk,	lassi, 	 etc. 	 All 	 these	 dif fer ent	 kinds	 of 	 food 	 pr ovide	 us	 with 	 nutrients	
to 	 keep 	 us 	 healthy 	 and	 active. 	 It	 is 	 important	 to	 know 	 what 	 food	 to	 eat 	 in	
or der	 to	 stay	 healthy.	 The	 science	 of	 food 	 and 	 nutrients	 and	 their	 action	
on 	 our 	health	 is	 called	Nutrition.
Learning Objectives 
After	completing	this 	chapter	the	lear ner 	 will 	 be 	able 	to 	 —	
•	 define 	 the 	ter ms 	 —	food,	nutrition,	nutrients, 	health, 	fitness	
and 	the 	 r ole 	of 	food	and	 nutrition	in	 maintaining	health.
•	 understand 	the	ter m, 	balanced 	diet	 and	apply	the 	concept 	in	
planning 	and	 consuming	diets.
•	 understand 	the	basis 	for	defining	 the	Recomm ended 	Dietary 	
Allowances 	(RDAs)	and 	the	dif fer ence 	 between	Dietary	
Requir ement 	and	 RDA.
•	 understand 	the	basis 	for	classifications	 of	fo ods 	into 	
appr opriate 	gr oups. 	
•	 analyse 	the	factors	which	influence	 adolesce nt 	food 	habits.
•	 identify 	 the	 causes, 	 symptoms	and 	nutritional 	 interventions	
related to eating disorders. 
Unit 1.indd   28 8/4/2022   2:50:43 PM
2024-25
Page 2


Human Ecology and Family Sciences – Part I
28
3
Food, Nutrition, 
Health and 
Fitness
3.1 Introduction 
The	 onset	 of	 adolescence	 brings	 with 	 it 	 many 	 pr ofound 	 changes.	 The	 gr owth	
rate 	 speeds 	 up 	 dramatically. 	 This	 gr owth 	 spurt	 occurs	 due	 to	 the	 activity	
of 	 hor mones	 that	 af fect 	 every	 or gan	 of	 the	 body	 and 	 this 	 makes	 healthy 	
eating	 very 	 important.	 The	 nutrient 	 needs 	 rise	 thr oughout 	 childhood,	 peak	
in adolescence and then level off or even diminish as the teenager becomes 
an 	 adult.	 The 	 saying	 ‘‘Y ou 	 ar e	 what	 you	 eat” 	 seems	 to 	 be 	 pr oven 	 true.	 W e	
eat 	 dif fer ent	 kinds 	 of	 food	 such	 as	dal, chapatti, bread, rice, vegetables, 
milk,	lassi, 	 etc. 	 All 	 these	 dif fer ent	 kinds	 of 	 food 	 pr ovide	 us	 with 	 nutrients	
to 	 keep 	 us 	 healthy 	 and	 active. 	 It	 is 	 important	 to	 know 	 what 	 food	 to	 eat 	 in	
or der	 to	 stay	 healthy.	 The	 science	 of	 food 	 and 	 nutrients	 and	 their	 action	
on 	 our 	health	 is	 called	Nutrition.
Learning Objectives 
After	completing	this 	chapter	the	lear ner 	 will 	 be 	able 	to 	 —	
•	 define 	 the 	ter ms 	 —	food,	nutrition,	nutrients, 	health, 	fitness	
and 	the 	 r ole 	of 	food	and	 nutrition	in	 maintaining	health.
•	 understand 	the	ter m, 	balanced 	diet	 and	apply	the 	concept 	in	
planning 	and	 consuming	diets.
•	 understand 	the	basis 	for	defining	 the	Recomm ended 	Dietary 	
Allowances 	(RDAs)	and 	the	dif fer ence 	 between	Dietary	
Requir ement 	and	 RDA.
•	 understand 	the	basis 	for	classifications	 of	fo ods 	into 	
appr opriate 	gr oups. 	
•	 analyse 	the	factors	which	influence	 adolesce nt 	food 	habits.
•	 identify 	 the	 causes, 	 symptoms	and 	nutritional 	 interventions	
related to eating disorders. 
Unit 1.indd   28 8/4/2022   2:50:43 PM
2024-25
29
Nutrition 	 and	 health, 	 in	 fact,	 ar e 	 two	 sides 	 of	 the 	 same	 coin.	 They 	
ar e,	 ther efor e, 	 inseparable. 	 Health	 depends	 to	 a	 lar ge	 extent	 on	 nutrition,	
and	 nutrition 	 depends	 on 	 the 	 food 	 intake. 	 So 	food, is the most important 
single factor for health and fitness.
Let us define and describe food, nutrition, health and fitness
•	 Food 	 	 	 can	 be	 defined 	 as 	 anything	 solid 	 or	 liquid	 which	 when	 swallowed, 	 	
digested 	 and 	 assimilated	 in 	 the 	 body 	 pr ovides	 it	 with	 essential	 substances	
called 	 nutrients	 and	 keeps	 it 	 well.	 It	 is	 the 	 basic	 necessity	 of 	 life. 	 Food 	
supplies 	 ener gy,	 enables	 gr owth	 and	 r epair 	 of 	 tissues	 and	 or gans.	 It 	
also 	pr otects 	the	 body	 fr om 	 disease 	and	 r egulates 	 body 	functions.
•	 Nutrition 	 is	 defined	 as 	 the 	 science 	 of	 foods,	 nutrients	 and 	 other 	
substances 	 they	 contain;	 and	 of	 their	 actions 	 within	 the 	 body	 including	
ingestion, digestion, absorption, metabolism and excretion. While 
this 	 summarises 	 the 	 physiological	 dimensions, 	 nutrition	 has 	 social, 	
psychological and economic dimensions too. 
•	 Nutrients 	 ar e	 the	 constituents	 in 	 food 	 that	 must	 be	 supplied	 to 	 the 	
body	 in 	 suitable	 amounts. 	 These	 include	 carbohydrates, 	 pr oteins,	 fats, 	
minerals, 	 vitamins, 	 water 	 and	 fibr e. 	 W e 	 need	 a 	 wide	 range	 of 	 nutrients	
to	 keep 	 ourselves	 healthy. 	 Most	 foods	 contain	 mor e	 than 	 one	 nutrient 	
such	 as 	 milk	 has 	 pr oteins,	 fats,	 etc.	 Nutrients	 can 	 be 	 classified	 as 	
macr onutrients 	 and	 micr onutrients	 on	 the	 basis	 of 	 the	 r equir ed 	
quantity 	 to	 be	 consumed	 by	 us	 everyday.	 The 	 figur e	 on 	 the	 next 	 page 	
shows 	 us	 the	distinction	between	 macr onutrients 	and 	micr onutrients.
3.2 Balanced Diet
A	 balanced 	 diet	 is 	 one	 which 	 includes 	 a 	 variety	 of	 foods	 in	 adequate 	 amounts 	
and	 corr ect 	 pr oportions 	 to	 meet	 the	 day’s	 r equir ements 	 of	 all	 essential	
nutrients 	 such 	 as 	 pr oteins,	 carbohydrates, 	 fats, 	 vitamins,	 minerals, 	 water ,	
and	 fibr e. 	 Such	 a 	 diet	 helps	 to 	 pr omote 	 and	 pr eserve	 good 	 health 	 and	
also 	 pr ovides 	 a 	 safety 	 mar gin	 or	 r eserve	 of 	 nutrients	 to	 withstand 	 short 	
durations 	of	deprivation	when 	they 	 ar e 	not	supplied	by	the	 diet.
The 	 safety 	 mar gin 	 takes 	 car e 	 of	 the 	 days 	 we 	 fast,	 or	 the	 short-ter m	
deficiency 	 of	 certain 	 nutrients	 in 	 the	 daily 	 diet. 	 If	 the	 balanced	 diet	 meets 	
the	 Recommended 	 Dietary	 Allowances	 (RDAs)	 for 	 an	 individual,	 then	 the	
safety 	 mar gin 	 is	 alr eady	 included 	 since	 RDAs	 ar e	 for mulated	 keeping 	 extra	
allowances 	in	mind.	
Recommended Dietary Allowances = Requirements + Margin of safety
A	balanced 	 diet 	takes	 car e 	of	 the	 following	 aspects.
1.	 Includes 	a	 variety 	 of	food	items
2.	 Meets 	 the	RDA	 for 	 all 	 nutrients
3.	 Includes 	nutrients 	in 	 corr ect 	 pr oportions
Food, Nutrition, Health and Fitness
Unit 1.indd   29 8/4/2022   2:50:43 PM
2024-25
Page 3


Human Ecology and Family Sciences – Part I
28
3
Food, Nutrition, 
Health and 
Fitness
3.1 Introduction 
The	 onset	 of	 adolescence	 brings	 with 	 it 	 many 	 pr ofound 	 changes.	 The	 gr owth	
rate 	 speeds 	 up 	 dramatically. 	 This	 gr owth 	 spurt	 occurs	 due	 to	 the	 activity	
of 	 hor mones	 that	 af fect 	 every	 or gan	 of	 the	 body	 and 	 this 	 makes	 healthy 	
eating	 very 	 important.	 The	 nutrient 	 needs 	 rise	 thr oughout 	 childhood,	 peak	
in adolescence and then level off or even diminish as the teenager becomes 
an 	 adult.	 The 	 saying	 ‘‘Y ou 	 ar e	 what	 you	 eat” 	 seems	 to 	 be 	 pr oven 	 true.	 W e	
eat 	 dif fer ent	 kinds 	 of	 food	 such	 as	dal, chapatti, bread, rice, vegetables, 
milk,	lassi, 	 etc. 	 All 	 these	 dif fer ent	 kinds	 of 	 food 	 pr ovide	 us	 with 	 nutrients	
to 	 keep 	 us 	 healthy 	 and	 active. 	 It	 is 	 important	 to	 know 	 what 	 food	 to	 eat 	 in	
or der	 to	 stay	 healthy.	 The	 science	 of	 food 	 and 	 nutrients	 and	 their	 action	
on 	 our 	health	 is	 called	Nutrition.
Learning Objectives 
After	completing	this 	chapter	the	lear ner 	 will 	 be 	able 	to 	 —	
•	 define 	 the 	ter ms 	 —	food,	nutrition,	nutrients, 	health, 	fitness	
and 	the 	 r ole 	of 	food	and	 nutrition	in	 maintaining	health.
•	 understand 	the	ter m, 	balanced 	diet	 and	apply	the 	concept 	in	
planning 	and	 consuming	diets.
•	 understand 	the	basis 	for	defining	 the	Recomm ended 	Dietary 	
Allowances 	(RDAs)	and 	the	dif fer ence 	 between	Dietary	
Requir ement 	and	 RDA.
•	 understand 	the	basis 	for	classifications	 of	fo ods 	into 	
appr opriate 	gr oups. 	
•	 analyse 	the	factors	which	influence	 adolesce nt 	food 	habits.
•	 identify 	 the	 causes, 	 symptoms	and 	nutritional 	 interventions	
related to eating disorders. 
Unit 1.indd   28 8/4/2022   2:50:43 PM
2024-25
29
Nutrition 	 and	 health, 	 in	 fact,	 ar e 	 two	 sides 	 of	 the 	 same	 coin.	 They 	
ar e,	 ther efor e, 	 inseparable. 	 Health	 depends	 to	 a	 lar ge	 extent	 on	 nutrition,	
and	 nutrition 	 depends	 on 	 the 	 food 	 intake. 	 So 	food, is the most important 
single factor for health and fitness.
Let us define and describe food, nutrition, health and fitness
•	 Food 	 	 	 can	 be	 defined 	 as 	 anything	 solid 	 or	 liquid	 which	 when	 swallowed, 	 	
digested 	 and 	 assimilated	 in 	 the 	 body 	 pr ovides	 it	 with	 essential	 substances	
called 	 nutrients	 and	 keeps	 it 	 well.	 It	 is	 the 	 basic	 necessity	 of 	 life. 	 Food 	
supplies 	 ener gy,	 enables	 gr owth	 and	 r epair 	 of 	 tissues	 and	 or gans.	 It 	
also 	pr otects 	the	 body	 fr om 	 disease 	and	 r egulates 	 body 	functions.
•	 Nutrition 	 is	 defined	 as 	 the 	 science 	 of	 foods,	 nutrients	 and 	 other 	
substances 	 they	 contain;	 and	 of	 their	 actions 	 within	 the 	 body	 including	
ingestion, digestion, absorption, metabolism and excretion. While 
this 	 summarises 	 the 	 physiological	 dimensions, 	 nutrition	 has 	 social, 	
psychological and economic dimensions too. 
•	 Nutrients 	 ar e	 the	 constituents	 in 	 food 	 that	 must	 be	 supplied	 to 	 the 	
body	 in 	 suitable	 amounts. 	 These	 include	 carbohydrates, 	 pr oteins,	 fats, 	
minerals, 	 vitamins, 	 water 	 and	 fibr e. 	 W e 	 need	 a 	 wide	 range	 of 	 nutrients	
to	 keep 	 ourselves	 healthy. 	 Most	 foods	 contain	 mor e	 than 	 one	 nutrient 	
such	 as 	 milk	 has 	 pr oteins,	 fats,	 etc.	 Nutrients	 can 	 be 	 classified	 as 	
macr onutrients 	 and	 micr onutrients	 on	 the	 basis	 of 	 the	 r equir ed 	
quantity 	 to	 be	 consumed	 by	 us	 everyday.	 The 	 figur e	 on 	 the	 next 	 page 	
shows 	 us	 the	distinction	between	 macr onutrients 	and 	micr onutrients.
3.2 Balanced Diet
A	 balanced 	 diet	 is 	 one	 which 	 includes 	 a 	 variety	 of	 foods	 in	 adequate 	 amounts 	
and	 corr ect 	 pr oportions 	 to	 meet	 the	 day’s	 r equir ements 	 of	 all	 essential	
nutrients 	 such 	 as 	 pr oteins,	 carbohydrates, 	 fats, 	 vitamins,	 minerals, 	 water ,	
and	 fibr e. 	 Such	 a 	 diet	 helps	 to 	 pr omote 	 and	 pr eserve	 good 	 health 	 and	
also 	 pr ovides 	 a 	 safety 	 mar gin	 or	 r eserve	 of 	 nutrients	 to	 withstand 	 short 	
durations 	of	deprivation	when 	they 	 ar e 	not	supplied	by	the	 diet.
The 	 safety 	 mar gin 	 takes 	 car e 	 of	 the 	 days 	 we 	 fast,	 or	 the	 short-ter m	
deficiency 	 of	 certain 	 nutrients	 in 	 the	 daily 	 diet. 	 If	 the	 balanced	 diet	 meets 	
the	 Recommended 	 Dietary	 Allowances	 (RDAs)	 for 	 an	 individual,	 then	 the	
safety 	 mar gin 	 is	 alr eady	 included 	 since	 RDAs	 ar e	 for mulated	 keeping 	 extra	
allowances 	in	mind.	
Recommended Dietary Allowances = Requirements + Margin of safety
A	balanced 	 diet 	takes	 car e 	of	 the	 following	 aspects.
1.	 Includes 	a	 variety 	 of	food	items
2.	 Meets 	 the	RDA	 for 	 all 	 nutrients
3.	 Includes 	nutrients 	in 	 corr ect 	 pr oportions
Food, Nutrition, Health and Fitness
Unit 1.indd   29 8/4/2022   2:50:43 PM
2024-25
Human Ecology and Family Sciences – Part I
30
Nutrients
    Macronutrients           Micronutrients
(Requi Red in la Rge amounts by the body )   (Requi Red in small amounts by the body )
c arb Ohydrates Iron
Iodine
Calcium
Minerals
Vitamins
f ibre /r OUghage Water f ats Pr Oteins Figure 1: Basic Nutrie Nts i N Our FOOd Unit 1.indd   30 8/4/2022   2:50:44 PM
2024-25
Page 4


Human Ecology and Family Sciences – Part I
28
3
Food, Nutrition, 
Health and 
Fitness
3.1 Introduction 
The	 onset	 of	 adolescence	 brings	 with 	 it 	 many 	 pr ofound 	 changes.	 The	 gr owth	
rate 	 speeds 	 up 	 dramatically. 	 This	 gr owth 	 spurt	 occurs	 due	 to	 the	 activity	
of 	 hor mones	 that	 af fect 	 every	 or gan	 of	 the	 body	 and 	 this 	 makes	 healthy 	
eating	 very 	 important.	 The	 nutrient 	 needs 	 rise	 thr oughout 	 childhood,	 peak	
in adolescence and then level off or even diminish as the teenager becomes 
an 	 adult.	 The 	 saying	 ‘‘Y ou 	 ar e	 what	 you	 eat” 	 seems	 to 	 be 	 pr oven 	 true.	 W e	
eat 	 dif fer ent	 kinds 	 of	 food	 such	 as	dal, chapatti, bread, rice, vegetables, 
milk,	lassi, 	 etc. 	 All 	 these	 dif fer ent	 kinds	 of 	 food 	 pr ovide	 us	 with 	 nutrients	
to 	 keep 	 us 	 healthy 	 and	 active. 	 It	 is 	 important	 to	 know 	 what 	 food	 to	 eat 	 in	
or der	 to	 stay	 healthy.	 The	 science	 of	 food 	 and 	 nutrients	 and	 their	 action	
on 	 our 	health	 is	 called	Nutrition.
Learning Objectives 
After	completing	this 	chapter	the	lear ner 	 will 	 be 	able 	to 	 —	
•	 define 	 the 	ter ms 	 —	food,	nutrition,	nutrients, 	health, 	fitness	
and 	the 	 r ole 	of 	food	and	 nutrition	in	 maintaining	health.
•	 understand 	the	ter m, 	balanced 	diet	 and	apply	the 	concept 	in	
planning 	and	 consuming	diets.
•	 understand 	the	basis 	for	defining	 the	Recomm ended 	Dietary 	
Allowances 	(RDAs)	and 	the	dif fer ence 	 between	Dietary	
Requir ement 	and	 RDA.
•	 understand 	the	basis 	for	classifications	 of	fo ods 	into 	
appr opriate 	gr oups. 	
•	 analyse 	the	factors	which	influence	 adolesce nt 	food 	habits.
•	 identify 	 the	 causes, 	 symptoms	and 	nutritional 	 interventions	
related to eating disorders. 
Unit 1.indd   28 8/4/2022   2:50:43 PM
2024-25
29
Nutrition 	 and	 health, 	 in	 fact,	 ar e 	 two	 sides 	 of	 the 	 same	 coin.	 They 	
ar e,	 ther efor e, 	 inseparable. 	 Health	 depends	 to	 a	 lar ge	 extent	 on	 nutrition,	
and	 nutrition 	 depends	 on 	 the 	 food 	 intake. 	 So 	food, is the most important 
single factor for health and fitness.
Let us define and describe food, nutrition, health and fitness
•	 Food 	 	 	 can	 be	 defined 	 as 	 anything	 solid 	 or	 liquid	 which	 when	 swallowed, 	 	
digested 	 and 	 assimilated	 in 	 the 	 body 	 pr ovides	 it	 with	 essential	 substances	
called 	 nutrients	 and	 keeps	 it 	 well.	 It	 is	 the 	 basic	 necessity	 of 	 life. 	 Food 	
supplies 	 ener gy,	 enables	 gr owth	 and	 r epair 	 of 	 tissues	 and	 or gans.	 It 	
also 	pr otects 	the	 body	 fr om 	 disease 	and	 r egulates 	 body 	functions.
•	 Nutrition 	 is	 defined	 as 	 the 	 science 	 of	 foods,	 nutrients	 and 	 other 	
substances 	 they	 contain;	 and	 of	 their	 actions 	 within	 the 	 body	 including	
ingestion, digestion, absorption, metabolism and excretion. While 
this 	 summarises 	 the 	 physiological	 dimensions, 	 nutrition	 has 	 social, 	
psychological and economic dimensions too. 
•	 Nutrients 	 ar e	 the	 constituents	 in 	 food 	 that	 must	 be	 supplied	 to 	 the 	
body	 in 	 suitable	 amounts. 	 These	 include	 carbohydrates, 	 pr oteins,	 fats, 	
minerals, 	 vitamins, 	 water 	 and	 fibr e. 	 W e 	 need	 a 	 wide	 range	 of 	 nutrients	
to	 keep 	 ourselves	 healthy. 	 Most	 foods	 contain	 mor e	 than 	 one	 nutrient 	
such	 as 	 milk	 has 	 pr oteins,	 fats,	 etc.	 Nutrients	 can 	 be 	 classified	 as 	
macr onutrients 	 and	 micr onutrients	 on	 the	 basis	 of 	 the	 r equir ed 	
quantity 	 to	 be	 consumed	 by	 us	 everyday.	 The 	 figur e	 on 	 the	 next 	 page 	
shows 	 us	 the	distinction	between	 macr onutrients 	and 	micr onutrients.
3.2 Balanced Diet
A	 balanced 	 diet	 is 	 one	 which 	 includes 	 a 	 variety	 of	 foods	 in	 adequate 	 amounts 	
and	 corr ect 	 pr oportions 	 to	 meet	 the	 day’s	 r equir ements 	 of	 all	 essential	
nutrients 	 such 	 as 	 pr oteins,	 carbohydrates, 	 fats, 	 vitamins,	 minerals, 	 water ,	
and	 fibr e. 	 Such	 a 	 diet	 helps	 to 	 pr omote 	 and	 pr eserve	 good 	 health 	 and	
also 	 pr ovides 	 a 	 safety 	 mar gin	 or	 r eserve	 of 	 nutrients	 to	 withstand 	 short 	
durations 	of	deprivation	when 	they 	 ar e 	not	supplied	by	the	 diet.
The 	 safety 	 mar gin 	 takes 	 car e 	 of	 the 	 days 	 we 	 fast,	 or	 the	 short-ter m	
deficiency 	 of	 certain 	 nutrients	 in 	 the	 daily 	 diet. 	 If	 the	 balanced	 diet	 meets 	
the	 Recommended 	 Dietary	 Allowances	 (RDAs)	 for 	 an	 individual,	 then	 the	
safety 	 mar gin 	 is	 alr eady	 included 	 since	 RDAs	 ar e	 for mulated	 keeping 	 extra	
allowances 	in	mind.	
Recommended Dietary Allowances = Requirements + Margin of safety
A	balanced 	 diet 	takes	 car e 	of	 the	 following	 aspects.
1.	 Includes 	a	 variety 	 of	food	items
2.	 Meets 	 the	RDA	 for 	 all 	 nutrients
3.	 Includes 	nutrients 	in 	 corr ect 	 pr oportions
Food, Nutrition, Health and Fitness
Unit 1.indd   29 8/4/2022   2:50:43 PM
2024-25
Human Ecology and Family Sciences – Part I
30
Nutrients
    Macronutrients           Micronutrients
(Requi Red in la Rge amounts by the body )   (Requi Red in small amounts by the body )
c arb Ohydrates Iron
Iodine
Calcium
Minerals
Vitamins
f ibre /r OUghage Water f ats Pr Oteins Figure 1: Basic Nutrie Nts i N Our FOOd Unit 1.indd   30 8/4/2022   2:50:44 PM
2024-25
31
4.	 Pr ovides 	a	safety 	 mar gin 	 for 	nutrients
5.	 Pr omotes 	 and	pr eserves 	good	health
6.	 Maintains 	acceptable	body	 weight	for	 height	
3.3 Health and Fitness
Accor ding 	 to 	 W orld 	 Health 	 Or ganisation 	 (WHO) 	 ‘‘Health is the state 
of 	 complete 	 physical, 	 emotional, 	 and 	 social 	 well-being, 	 not 	 mer ely 	 the	
absence 	 of 	 diseases 	 or 	 infir mity.’’ 	 This 	 definition 	 has 	 r emained 	 unchanged	
since 	 1948.
All 	 of	 us 	 want 	 to	 maintain	 positive	 health,	 i.e.,	 a 	 per fect	 blend 	 of 	 physical,	
social	 and 	 mental.	 T aking 	 adequate	 amounts	 of 	 essential 	 nutrients 	 in	 our	
diet is necessary to maintain positive health. 
Physical 	 health	 is 	 pr obably	 the 	 most	 easily	 understood	 aspect. 	 Mental 	
health can be defined as a state of emotional and psychological  
well-being in which an individual is able to use her or his cognitive 
and emotional capabilities, function in society, and meet the ordinary 
demands of everyday life. 	 In	 other	 wor ds, 	 the	 absence	 of 	 a 	 r ecognised	
mental	 disor der 	 is	 not 	 necessarily	 an	 indicator	 of	 mental	 health. 	 One	 way 	
to 	 assess 	 mental	 health	 is	 to 	 see 	 how 	 ef fectively	 and 	 successfully	 a 	 person 	
functions. 	 Feeling 	 capable	 and 	 competent,	 being	 able	 to 	 handle	 nor mal	
levels of stress, maintaining satisfying relationships, and leading an 
independent 	 life; 	 and 	 being	 able	 to	 ‘bounce	 back’ 	 or	 r ecover	 fr om 	 dif ficult	
situations 	 ar e 	all	signs 	of 	good 	 mental	health.
Physical fitness is 	 good	 bodily	 health;	 it	 is 	 the	 r esult	 of	 r egular	 exer cise,	
pr oper	 diet 	 and 	 nutrition,	 and 	 pr oper 	 r est	 for 	 physical	 r ecovery. 	 The	 ter m	
physical	 fitness	 is	 used 	 in 	 two 	 ways:	 general	 fitness 	 (a	 state 	 of 	 health 	
and	 well-being) 	 and	 specific	 fitness	 (a	 task-oriented	 definition 	 based	 on	
the	 ability 	 to	 per for m	 specific	 aspects	 of	 sports	 or	 occupations). 	 Physical	
fitness 	 is 	 the	 capacity 	 of 	 the 	 heart,	 blood	 vessels,	 lungs, 	 and 	 muscles	 to 	
function 	 at 	 optimal 	 ef ficiency.	 Earlier ,	 fitness	 was 	 defined	 as 	 the	 capacity	 to 	
carry 	 out 	 the 	 day’s 	 activities	 without	 undue 	 fatigue. 	 Automation,	 incr eased 	
leisur e 	 time, 	 and 	 changes 	 in 	 lifestyles	 following 	 the	 Industrial 	 Revolution 	
meant 	 that 	 this	 criterion 	 was	 no 	 longer	 suf ficient.	 In	 the	 pr esent 	 context, 	
optimum 	 ef ficiency 	 is	the 	key.	
Physical 	 fitness 	 is 	 now	 defined	 as	 the	 body’s	 ability	 to	 function	
ef ficiently 	 and	 ef fectively	 in	 work 	 and 	 leisur e	 activities, 	 to 	 be 	 healthy,	 to 	
r esist 	 diseases 	 and 	 to	 meet 	 emer gency	 situations. 	 Fitness	 can 	 also	 be	
divided	 into 	 five	 categories:	 aer obic	 fitness,	 muscular	 str ength, 	 muscular 	
endurance, 	 flexibility, 	 and	 body	 composition.	 Being 	 fit	 pr epar es 	 one 	 to	
meet	 mental 	 and	 emotional 	 challenges.	 One 	 feels	 str ong 	 and	 ener getic	 if	
one	 is 	 fit. 	 Fitness	 pr ovides 	 one 	 with	 the	 ability	 to	 meet	 r outine	 physical	
demands 	 with	 enough	 r eserve	 ener gy	 to	 rise	 to	 a	 sudden 	 challenge, 	 such	
as	 running 	to	catch	a	bus.
Food, Nutrition, Health and Fitness
Unit 1.indd   31 8/4/2022   2:50:44 PM
2024-25
Page 5


Human Ecology and Family Sciences – Part I
28
3
Food, Nutrition, 
Health and 
Fitness
3.1 Introduction 
The	 onset	 of	 adolescence	 brings	 with 	 it 	 many 	 pr ofound 	 changes.	 The	 gr owth	
rate 	 speeds 	 up 	 dramatically. 	 This	 gr owth 	 spurt	 occurs	 due	 to	 the	 activity	
of 	 hor mones	 that	 af fect 	 every	 or gan	 of	 the	 body	 and 	 this 	 makes	 healthy 	
eating	 very 	 important.	 The	 nutrient 	 needs 	 rise	 thr oughout 	 childhood,	 peak	
in adolescence and then level off or even diminish as the teenager becomes 
an 	 adult.	 The 	 saying	 ‘‘Y ou 	 ar e	 what	 you	 eat” 	 seems	 to 	 be 	 pr oven 	 true.	 W e	
eat 	 dif fer ent	 kinds 	 of	 food	 such	 as	dal, chapatti, bread, rice, vegetables, 
milk,	lassi, 	 etc. 	 All 	 these	 dif fer ent	 kinds	 of 	 food 	 pr ovide	 us	 with 	 nutrients	
to 	 keep 	 us 	 healthy 	 and	 active. 	 It	 is 	 important	 to	 know 	 what 	 food	 to	 eat 	 in	
or der	 to	 stay	 healthy.	 The	 science	 of	 food 	 and 	 nutrients	 and	 their	 action	
on 	 our 	health	 is	 called	Nutrition.
Learning Objectives 
After	completing	this 	chapter	the	lear ner 	 will 	 be 	able 	to 	 —	
•	 define 	 the 	ter ms 	 —	food,	nutrition,	nutrients, 	health, 	fitness	
and 	the 	 r ole 	of 	food	and	 nutrition	in	 maintaining	health.
•	 understand 	the	ter m, 	balanced 	diet	 and	apply	the 	concept 	in	
planning 	and	 consuming	diets.
•	 understand 	the	basis 	for	defining	 the	Recomm ended 	Dietary 	
Allowances 	(RDAs)	and 	the	dif fer ence 	 between	Dietary	
Requir ement 	and	 RDA.
•	 understand 	the	basis 	for	classifications	 of	fo ods 	into 	
appr opriate 	gr oups. 	
•	 analyse 	the	factors	which	influence	 adolesce nt 	food 	habits.
•	 identify 	 the	 causes, 	 symptoms	and 	nutritional 	 interventions	
related to eating disorders. 
Unit 1.indd   28 8/4/2022   2:50:43 PM
2024-25
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Nutrition 	 and	 health, 	 in	 fact,	 ar e 	 two	 sides 	 of	 the 	 same	 coin.	 They 	
ar e,	 ther efor e, 	 inseparable. 	 Health	 depends	 to	 a	 lar ge	 extent	 on	 nutrition,	
and	 nutrition 	 depends	 on 	 the 	 food 	 intake. 	 So 	food, is the most important 
single factor for health and fitness.
Let us define and describe food, nutrition, health and fitness
•	 Food 	 	 	 can	 be	 defined 	 as 	 anything	 solid 	 or	 liquid	 which	 when	 swallowed, 	 	
digested 	 and 	 assimilated	 in 	 the 	 body 	 pr ovides	 it	 with	 essential	 substances	
called 	 nutrients	 and	 keeps	 it 	 well.	 It	 is	 the 	 basic	 necessity	 of 	 life. 	 Food 	
supplies 	 ener gy,	 enables	 gr owth	 and	 r epair 	 of 	 tissues	 and	 or gans.	 It 	
also 	pr otects 	the	 body	 fr om 	 disease 	and	 r egulates 	 body 	functions.
•	 Nutrition 	 is	 defined	 as 	 the 	 science 	 of	 foods,	 nutrients	 and 	 other 	
substances 	 they	 contain;	 and	 of	 their	 actions 	 within	 the 	 body	 including	
ingestion, digestion, absorption, metabolism and excretion. While 
this 	 summarises 	 the 	 physiological	 dimensions, 	 nutrition	 has 	 social, 	
psychological and economic dimensions too. 
•	 Nutrients 	 ar e	 the	 constituents	 in 	 food 	 that	 must	 be	 supplied	 to 	 the 	
body	 in 	 suitable	 amounts. 	 These	 include	 carbohydrates, 	 pr oteins,	 fats, 	
minerals, 	 vitamins, 	 water 	 and	 fibr e. 	 W e 	 need	 a 	 wide	 range	 of 	 nutrients	
to	 keep 	 ourselves	 healthy. 	 Most	 foods	 contain	 mor e	 than 	 one	 nutrient 	
such	 as 	 milk	 has 	 pr oteins,	 fats,	 etc.	 Nutrients	 can 	 be 	 classified	 as 	
macr onutrients 	 and	 micr onutrients	 on	 the	 basis	 of 	 the	 r equir ed 	
quantity 	 to	 be	 consumed	 by	 us	 everyday.	 The 	 figur e	 on 	 the	 next 	 page 	
shows 	 us	 the	distinction	between	 macr onutrients 	and 	micr onutrients.
3.2 Balanced Diet
A	 balanced 	 diet	 is 	 one	 which 	 includes 	 a 	 variety	 of	 foods	 in	 adequate 	 amounts 	
and	 corr ect 	 pr oportions 	 to	 meet	 the	 day’s	 r equir ements 	 of	 all	 essential	
nutrients 	 such 	 as 	 pr oteins,	 carbohydrates, 	 fats, 	 vitamins,	 minerals, 	 water ,	
and	 fibr e. 	 Such	 a 	 diet	 helps	 to 	 pr omote 	 and	 pr eserve	 good 	 health 	 and	
also 	 pr ovides 	 a 	 safety 	 mar gin	 or	 r eserve	 of 	 nutrients	 to	 withstand 	 short 	
durations 	of	deprivation	when 	they 	 ar e 	not	supplied	by	the	 diet.
The 	 safety 	 mar gin 	 takes 	 car e 	 of	 the 	 days 	 we 	 fast,	 or	 the	 short-ter m	
deficiency 	 of	 certain 	 nutrients	 in 	 the	 daily 	 diet. 	 If	 the	 balanced	 diet	 meets 	
the	 Recommended 	 Dietary	 Allowances	 (RDAs)	 for 	 an	 individual,	 then	 the	
safety 	 mar gin 	 is	 alr eady	 included 	 since	 RDAs	 ar e	 for mulated	 keeping 	 extra	
allowances 	in	mind.	
Recommended Dietary Allowances = Requirements + Margin of safety
A	balanced 	 diet 	takes	 car e 	of	 the	 following	 aspects.
1.	 Includes 	a	 variety 	 of	food	items
2.	 Meets 	 the	RDA	 for 	 all 	 nutrients
3.	 Includes 	nutrients 	in 	 corr ect 	 pr oportions
Food, Nutrition, Health and Fitness
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Nutrients
    Macronutrients           Micronutrients
(Requi Red in la Rge amounts by the body )   (Requi Red in small amounts by the body )
c arb Ohydrates Iron
Iodine
Calcium
Minerals
Vitamins
f ibre /r OUghage Water f ats Pr Oteins Figure 1: Basic Nutrie Nts i N Our FOOd Unit 1.indd   30 8/4/2022   2:50:44 PM
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4.	 Pr ovides 	a	safety 	 mar gin 	 for 	nutrients
5.	 Pr omotes 	 and	pr eserves 	good	health
6.	 Maintains 	acceptable	body	 weight	for	 height	
3.3 Health and Fitness
Accor ding 	 to 	 W orld 	 Health 	 Or ganisation 	 (WHO) 	 ‘‘Health is the state 
of 	 complete 	 physical, 	 emotional, 	 and 	 social 	 well-being, 	 not 	 mer ely 	 the	
absence 	 of 	 diseases 	 or 	 infir mity.’’ 	 This 	 definition 	 has 	 r emained 	 unchanged	
since 	 1948.
All 	 of	 us 	 want 	 to	 maintain	 positive	 health,	 i.e.,	 a 	 per fect	 blend 	 of 	 physical,	
social	 and 	 mental.	 T aking 	 adequate	 amounts	 of 	 essential 	 nutrients 	 in	 our	
diet is necessary to maintain positive health. 
Physical 	 health	 is 	 pr obably	 the 	 most	 easily	 understood	 aspect. 	 Mental 	
health can be defined as a state of emotional and psychological  
well-being in which an individual is able to use her or his cognitive 
and emotional capabilities, function in society, and meet the ordinary 
demands of everyday life. 	 In	 other	 wor ds, 	 the	 absence	 of 	 a 	 r ecognised	
mental	 disor der 	 is	 not 	 necessarily	 an	 indicator	 of	 mental	 health. 	 One	 way 	
to 	 assess 	 mental	 health	 is	 to 	 see 	 how 	 ef fectively	 and 	 successfully	 a 	 person 	
functions. 	 Feeling 	 capable	 and 	 competent,	 being	 able	 to 	 handle	 nor mal	
levels of stress, maintaining satisfying relationships, and leading an 
independent 	 life; 	 and 	 being	 able	 to	 ‘bounce	 back’ 	 or	 r ecover	 fr om 	 dif ficult	
situations 	 ar e 	all	signs 	of 	good 	 mental	health.
Physical fitness is 	 good	 bodily	 health;	 it	 is 	 the	 r esult	 of	 r egular	 exer cise,	
pr oper	 diet 	 and 	 nutrition,	 and 	 pr oper 	 r est	 for 	 physical	 r ecovery. 	 The	 ter m	
physical	 fitness	 is	 used 	 in 	 two 	 ways:	 general	 fitness 	 (a	 state 	 of 	 health 	
and	 well-being) 	 and	 specific	 fitness	 (a	 task-oriented	 definition 	 based	 on	
the	 ability 	 to	 per for m	 specific	 aspects	 of	 sports	 or	 occupations). 	 Physical	
fitness 	 is 	 the	 capacity 	 of 	 the 	 heart,	 blood	 vessels,	 lungs, 	 and 	 muscles	 to 	
function 	 at 	 optimal 	 ef ficiency.	 Earlier ,	 fitness	 was 	 defined	 as 	 the	 capacity	 to 	
carry 	 out 	 the 	 day’s 	 activities	 without	 undue 	 fatigue. 	 Automation,	 incr eased 	
leisur e 	 time, 	 and 	 changes 	 in 	 lifestyles	 following 	 the	 Industrial 	 Revolution 	
meant 	 that 	 this	 criterion 	 was	 no 	 longer	 suf ficient.	 In	 the	 pr esent 	 context, 	
optimum 	 ef ficiency 	 is	the 	key.	
Physical 	 fitness 	 is 	 now	 defined	 as	 the	 body’s	 ability	 to	 function	
ef ficiently 	 and	 ef fectively	 in	 work 	 and 	 leisur e	 activities, 	 to 	 be 	 healthy,	 to 	
r esist 	 diseases 	 and 	 to	 meet 	 emer gency	 situations. 	 Fitness	 can 	 also	 be	
divided	 into 	 five	 categories:	 aer obic	 fitness,	 muscular	 str ength, 	 muscular 	
endurance, 	 flexibility, 	 and	 body	 composition.	 Being 	 fit	 pr epar es 	 one 	 to	
meet	 mental 	 and	 emotional 	 challenges.	 One 	 feels	 str ong 	 and	 ener getic	 if	
one	 is 	 fit. 	 Fitness	 pr ovides 	 one 	 with	 the	 ability	 to	 meet	 r outine	 physical	
demands 	 with	 enough	 r eserve	 ener gy	 to	 rise	 to	 a	 sudden 	 challenge, 	 such	
as	 running 	to	catch	a	bus.
Food, Nutrition, Health and Fitness
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Thus,	 health	 is 	 a	 state 	 of	 complete	 mental,	 physical 	 and 	 social	 well-
being 	 wher eas 	 fitness	 is 	 the 	 ability	 to 	 meet 	 the	 demands 	 of 	 a 	 physical	 task.	
A 	 well-nourished	 and	 fit	 person	 is	 better 	 able	 to 	 lear n 	 and	 has 	 mor e	 ener gy, 	
stamina, 	 and	 self-esteem.	 A	 healthy	 eating 	 patter n	 along	 with 	 r egular	
exer cise 	 will 	 certainly	 help	 to 	 r emain 	 fit.	 T eenagers 	 between	 the 	 ages	 of	 12 	
and	 18 	 who	 have	 unhealthy	 eating	 behaviours	 and 	 ar e	 under nourished	
develop eating disorders.
3.4 Using Basic Food Groups for 
Planning Balanced Diets
One 	 of 	 the	 simplest 	 ways	 to	 plan	 a	 balanced 	 diet	 is	 to	 divide	 foods	 into 	
gr oups	 and	 then 	 make 	 sur e	 that	 each 	 gr oup	 is	 included 	 in 	 the 	 meals. 	 A	
food	 gr oup 	 consists	 of	 dif fer ent	 foods	 which	 have	 common 	 characteristics. 	
These	 common 	 featur es	 may	 be	 the 	 sour ce 	 of	 food, 	 the	 physiological 	
function	 per for med, 	 or	the	nutrients 	 pr esent.
Foods 	 can	 be 	 gr ouped	 on 	 the 	 basis	 of 	 the	 pr edominant	 nutrients	
pr esent	 in 	 them.	 This	 classification	 varies 	 fr om 	 one 	 country 	 to 	 another	
depending 	 on	 many 	 factors.	 The	 five	 food 	 gr oup 	 classification 	 is 	 used	 in	
India	 as	 a	 guide	 to	 meal 	 planning. 	 Many	 factors 	 have	 been 	 consider ed	 while	
compiling	 these 	 gr oups	 such 	 as	 availability 	 of 	 food, 	 cost, 	 meal	 patter n, 	 and	
deficiency 	 diseases 	 pr evalent.	 Not 	 all	 foods 	 in 	 each 	 gr oup	 ar e 	 equal	 in	 their	
nutrient	 content.	 That	 is	 why	 a	 variety	 of	 foods	 fr om	 each	 gr oup	 should 	 be 	
included 	in 	the 	 diet.
A	 classification	 based	 on	 nutrients	 pr esent 	 will 	 ensur e 	 that	 all	 nutrients 	
ar e 	made	 available 	to 	 the	body 	and	 of fer 	 gr eater 	variety 	within 	the 	gr oup.	
Ther e 	 ar e	 five 	 basic	 food	 gr oups	 suggested 	 by 	 the	 Indian	 Council	 of 	
Medical	Resear ch 	 (ICMR).	These 	include:
•	 Cer eals, 	grains	and 	pr oducts
•	 Pulses 	and	 legumes
•	 Milk 	 and 	 meat	pr oducts
•	 Fruits 	 and 	 vegetables
•	 Fats 	and 	 sugars	
List 10 foods that you commonly eat. Identify the food group to which each food belongs. 
Then list the macronutrients and micronutrients present in the foods listed. Identify the 
foods which are the richest sources of energy.
Activity 1
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