Dietary and energy balance
Friday, 29 October 2021 9:31 AM
Dietary nutrients
- Provide energy
- Provide building blocks
- For growth development, maintenance, physical activities and brain
activities
- Classification of nutrients
○ Carbohydrates
○ Proteins
○ Lipids
○ Vitamins
○ Minerals
○ Water
○ Dietary fibres
- Essential nutrients
○ Must be ingested because
§ Body cannot synthesize or
§ Body cannot synthesize enough
○ E.g. essential amino acids
§ Methionine which the body can synthesize but not in
sufficient amounts
§ Using metabolic pathways
○ Essential fatty acids and most vitamins
○ Vitamins, mineral, water and dietary fibres are all essential
- Nonessential nutrients
○ Doesn’t mean its not as essential but means its not required in
the diet since we can synthesize in sufficient quantities
○ However they are generally obtained from food as well
○ E.g. carbohydrates (except dietary fibres), nonessential fatty
acids and nonessential amino acids
§ Alanine arginine and glutamine
§ Can live without carbohydrates but our body prefers to
have them as our energy source
- Macronutrients
○ Needed in large amounts
§ In order to sustain our body metabolic processes
○ E.g. carbohydrates proteins lipids and water
- Micronutrients
, - Macronutrients
○ Needed in large amounts
§ In order to sustain our body metabolic processes
○ E.g. carbohydrates proteins lipids and water
- Micronutrients
○ Needed in small amounts
○ Microgram to milligrams
○ E.g. vitamins and minerals
Dietary balance and the food pyramid
- Dietary balance is defined as the appropriate balance of different
nutrients to maintain health
- Pyramid
○ Foods high in sugar, fat and salt
§ Including processed meat
○ Fats spreads and oils
○ Red meats
○ Poultry fish
○ Eggs
○ Milk yoghurt and cheese
○ Wholemeal cereals and breads, potatoes, pasta, rice, legumes,
beans and nuts
○ Fruit and veg
Carbohydrates requirement
- Overconsumption causes excess calories and obesity
- Insufficiency leads to undernutrition
- Simple vs complex
○ Simple carbohydrates provide calories
§ Fruits / nuts / processed sugary foods
○ Complex digest more slowly but keep blood sugar more stable
§ Rice / barley etc
- Recommendation
○ Eat more fruits whole grain rice bread cereal legumes
○ Avoid processes refined simple sugars
- Based on risk of heart disease and obesity, WHO recommends
55-75% of total energy from carbohydrates with only 5-10% directly
from simple carbohydrates
Proteins in diet
- Proteins provide 22 AA
○ 9 are essential
§ Cannot be synthesized by body
§ EAAs
□ Histidine / isoleucine / leucine / lysine / methionine
/ phenylalanine / threonine / tryptophan / valine
Friday, 29 October 2021 9:31 AM
Dietary nutrients
- Provide energy
- Provide building blocks
- For growth development, maintenance, physical activities and brain
activities
- Classification of nutrients
○ Carbohydrates
○ Proteins
○ Lipids
○ Vitamins
○ Minerals
○ Water
○ Dietary fibres
- Essential nutrients
○ Must be ingested because
§ Body cannot synthesize or
§ Body cannot synthesize enough
○ E.g. essential amino acids
§ Methionine which the body can synthesize but not in
sufficient amounts
§ Using metabolic pathways
○ Essential fatty acids and most vitamins
○ Vitamins, mineral, water and dietary fibres are all essential
- Nonessential nutrients
○ Doesn’t mean its not as essential but means its not required in
the diet since we can synthesize in sufficient quantities
○ However they are generally obtained from food as well
○ E.g. carbohydrates (except dietary fibres), nonessential fatty
acids and nonessential amino acids
§ Alanine arginine and glutamine
§ Can live without carbohydrates but our body prefers to
have them as our energy source
- Macronutrients
○ Needed in large amounts
§ In order to sustain our body metabolic processes
○ E.g. carbohydrates proteins lipids and water
- Micronutrients
, - Macronutrients
○ Needed in large amounts
§ In order to sustain our body metabolic processes
○ E.g. carbohydrates proteins lipids and water
- Micronutrients
○ Needed in small amounts
○ Microgram to milligrams
○ E.g. vitamins and minerals
Dietary balance and the food pyramid
- Dietary balance is defined as the appropriate balance of different
nutrients to maintain health
- Pyramid
○ Foods high in sugar, fat and salt
§ Including processed meat
○ Fats spreads and oils
○ Red meats
○ Poultry fish
○ Eggs
○ Milk yoghurt and cheese
○ Wholemeal cereals and breads, potatoes, pasta, rice, legumes,
beans and nuts
○ Fruit and veg
Carbohydrates requirement
- Overconsumption causes excess calories and obesity
- Insufficiency leads to undernutrition
- Simple vs complex
○ Simple carbohydrates provide calories
§ Fruits / nuts / processed sugary foods
○ Complex digest more slowly but keep blood sugar more stable
§ Rice / barley etc
- Recommendation
○ Eat more fruits whole grain rice bread cereal legumes
○ Avoid processes refined simple sugars
- Based on risk of heart disease and obesity, WHO recommends
55-75% of total energy from carbohydrates with only 5-10% directly
from simple carbohydrates
Proteins in diet
- Proteins provide 22 AA
○ 9 are essential
§ Cannot be synthesized by body
§ EAAs
□ Histidine / isoleucine / leucine / lysine / methionine
/ phenylalanine / threonine / tryptophan / valine
