nutrition and energy balance

nutrition

• intake of food, considered in relation to the body’s dietary needs

• Good nutrition and a well balanced diet is a cornerstone of good health

• Malnutrition is when a person’s diet does not provide the right balance of nutrients for good health

micronutrients

• needed in tiny amounts compared to macronutrients

• ug or mg

• vitamins and minerals

Vitamin

• any group of organic compounds which are essential for normal growth and nutrition and are required in small quantities in the diet because they can’t be synthesised by the body

• small quantities = mg or ug per day

• Deprivation leads to development for a clinical deficiency disease and abnormal metabolic signs

• Restoration leads to a cure or prevents that disease and normalises metabolism

Roles of macronutrients

Carbohydrates:

• energy source, control of glucose and insulin metabolism, cholesterol and triglyceride metabolism

Lipid (fats)

• storing energy, regulation and cell signalling, insulating and protecting, aiding digestion

Proteins:

• growth and maintenance of cells and tissues, gene expression, hormones, antibodies, digestion, muscle contraction and movement

Vitamin classification

Water soluble

Fat Soluble

Water soluble vitamins

• B1

• B2

• B3

• B5

• B6

• B7

• B9

• B12

Fat soluble vitamins

• A

• D

• E

• K

Vitamin B9: folate

• folic acid, converts to folate

• They transfer one carbon fragments in many biosynthetic and catabolic reactions

• Metabolically closely related to B12

• important at times of increased cell division: pregnancy and developing foetus

• Deficiency leads to megaloblastic anaemia

folate and pregnancy

• normal recommended daily intake is 200ug a day

• 400ug a day is recommended for pregnant women and first 12 weeks

vitamin D

• a group of fat soluble compounds

• Most important for humans: D3 and D2

• Main source is sunlight

vitamin D deficiency

• v high levels of deficiency worldwide

• Deficiency causes rickets in children

• Deficiency causes osteomalacia in adults

Vitamin D deficiency risk groups

• older people

• People not exposed to the sun

• Breastfed infants/ breastfeeding mothers

• People with darker skin

• People with fat malabsorption issues

Vitamin B12

• lack of B12 causes body to produce abnormally large red blood cells that can’t function properly→ megaloblastic anaemia

• Most common B12 deficiency cause: pernicious anaemia

• Can also be lack of dietary intake or absorption issues including interactions with common medication like proton pump inhibitors and metformin

• B12 deficiency is common (1 in 10 for over 75s)

iron deficiency

• common global issue including developed countries

• leads to iron deficiency anaemia

• Common causes:

  • heavy menstrual bleeding

  • Bleeding from GI tract

  • Inadequate dietary intake

  • Malabsorption issues

Hypocalcaemia

• hypoparathyroidism

• Vit D deficiency

• Chronic liver disease

• Chronic kidney disease

• Acute kidney injury

Energy expenditure

• basal metabolism = energy required to keep your body functioning at rest: energy used to activities such as maintaining body temperature and supporting vital systems