Nutrition and Health 2023 PDF

Nutrition and Health MBBS stage 1 Nutrition and Metabolism Dr Despo Papachristodoulou  micronutrients vitamins, essential minerals, essential amino acids essential fatty acids only needed in tiny amounts ( g, mg or µg per day); Nutritionists mean this latter gr...

Nutrition and Health MBBS stage 1 Nutrition and Metabolism Dr Despo Papachristodoulou  micronutrients vitamins, essential minerals, essential amino acids essential fatty acids only needed in tiny amounts ( g, mg or µg per day); Nutritionists mean this latter group (i.e. micronutrients) when they refer to ‘nutrients’. How do we know how much X we need? How do we know how much X we are getting by eating a certain food?  Requirements Difficult to be specific about individual energy and nutrient requirements vary depending on age, gender, activity levels etc guidelines for groups within the population  What is the requirement for a nutrient? Classically, amount needed to prevent deficiency Societies expect more than that Storage for times of low/no intake Food Standards Agency Committee of Medical Aspects of Food Policy (COMA) Dietary reference values for Food, Energy and Nutrients for the United Kingdom  How is it done? Looking at : the intake of X in groups of people with no deficiency the intake in groups of people with deficiency intakes that would cure clinical deficiency intakes that are associated with a marker of nutritional adequacy (enzyme saturation, tissue concentration)  That allows to work out the estimated average requirement EAR  Normal distribution EAR RNI Blue is 1 sd. from the mean This accounts for about 68% of the population 2 standard deviations from the mean (blue and brown) account for about 95% three standard deviations (blue, brown and green) account for about 99.7%.  Dietary Reference Values (DRVs) Estimated Average Requirement (EAR) The notional mean requirement of a nutrient (for a group of healthy individuals in a population); Reference Nutrient Intake (RNI) Two standard deviations above the EAR, sufficient of a nutrient to meet the needs of most of the population; (Formerly termed: Recommended Daily Allowance.) Lower Reference Nutrient Intake (LRNI) Two standard deviations below the EAR; intakes of a nutrient below this level are almost certainly inadequate for most individuals.  e.g. Vitamin C (ascorbic acid) EAR for adults in the UK is 25mg ( 25mg per day is the estimated average requirement & sufficient for the needs of  50% of the population *). RNI for adults in the UK is 40mg ( 40mg vitamin C per day is sufficient to meet the needs of  95% of the population). LRNI for adults in the UK is 10mg (  diets containing < 10mg vitamin C per day would only provide sufficient for  5% of the population). * N.B. It follows that a diet containing < the RNI is not automatically providing insufficient vitamin C. Do we do the same for energy requirement? NO Why not?  For nutritional programmes for groups of people e.g. babies, pregnant women, children, adults, the elderly, ethnic groups For formulation of feeds for babies, schools, institutions for clinical nutrition i.e. patients on enteral or parenteral nutrition  How do we know how much X we are taking in ? Food tables In the UK the standard work is McCance and Widdowson’s The chemical composition of foods 1st edition 1946, latest 2021 Published by Public Health England and now called The composition of foods integrated dataset 2021  History, 1926 Robert McCance, medical student at KCL, grant of £30/year from the MRC to analyse the carbohydrate contents of raw and cooked fruits and vegetables. information needed for formulating diets for diabetic patients. This research project became the basis for his subsequent life’s work.  Obtaining data for the chemical composition of foods: Many samples of a particular food are analysed, the mean content of: available energy, water, protein, fat, carbohydrate, alcohol, vitamins, minerals, dietary fibre etc … can be calculated  Accurate? The data obtained from food tables will not have strict accuracy, e.g. fat content of milk varies with season but they can still be of use e.g in the analysis of an individual’s nutrient and energy intakes In formulation of diets where certain foods must be avoided e.g diets for diabetics, people with high cholesterol , on dialysis etc  Nutrition and Health Undernutrition Overnutrition  Undernutrition Major problem in many developing countries E.g. South Asia, sub-Saharan Africa, parts of South America  In the developed world Usually specific deficiencies i.e. proteins, vitamins, minerals Main groups: Elderly,at home on their own or in institutions Young people on junk food Some Asian women and children in traditional clothes Slimmers and people on fad diets Cancer and AIDS patients People with eating disorders Up to 40% of hospitalised patients  Overnutrition The main nutritional problem in the developed world (and increasing in the developing) Too much fat Too much sugar Too much salt Too much food in general  Body mass index = wt/ht2 (kg/m2) 18.5-24.9 Normal (ideal) 25- 29.9 Overweight (pre-obese) 30-34.9 Obesity grade 1 35-39.9 Obesity grade 2 >40 Obesity grade 3 Does this apply to everyone? Globally, the percentage of adults who were overweight or obese - grew from 23% to 34% between 1980 and 2008 In UK obesity 30 % and overweight and obesity 63% (Nov 2021) GOV.UK England 25.3% (which age group is worst?)  Prevalence of BMI >30 by social class, England 1998 30 25 20 Men 15 Women 10 5 0 I II III NM III M IV V Social class  Sugar consumption in food and drinks increases from Social Classes 1 to V UK sales of snacks and confectionery outstrip other European countries Sales of fizzy drinks have doubled in 15 years. In the UK Only 13% of children aged 5-15 eat five or more portions of fruit and vegetables a day 15% eat less than one portion of fruit and vegetables a day Fruit and vegetable consumption decreases from Social Classes I to V  Childhood obesity is particularly disturbing In the last 10 years: Obesity in 6 year olds has doubled to 9.6% Trebled in 15 year olds to 15% Junk food and lack of exercise UK 2018 : 1in 10 obese by age 5 1in 5 obese by age 11 Conditions associated with middle age are now appearing in children High cholesterol Type 2 diabetes  Consequences Cardiovascular disease Stroke Some cancers Hypertension Diabetes type 2 Gallstones Dental caries Gout Infertility Sleep apnoea Surgical risk Psychological distress Risks for cardiovascular disease High blood cholesterol Hypertension Smoking Inactivity obesity High blood pressure Often related to high salt intake average UK consumption 9g/day Max recommended is 6g Probably need 1g Some groups of the population at particular risk British of South Asian origin have higher incidence of strokes (and diabetes and hypertension) Deaths from stroke 55% higher in men and 41% in women compared to the general population in 1990s Salt features prominently in traditional diets Survey showed that few knew relationship between salt, high blood pressure and stroke  Coronary heart disease & stroke In 2000 Target for 2010 To reduce the death rate from coronary heart disease and stroke & related diseases in people under 75 by at least two fifths UK 2021 168,099 died from CVD 48,024 under 75 years old 7.6 million + living with CVD Since 1961 the UK death rate from heart and circulatory diseases (CVD) has declined by more than three quarters. Death rates have fallen more quickly than the actual number of deaths because people in this country are now living longer. The premature (under 75) CVD death rate for Glasgow (134 per 100,000 people) is more than three times than that for Mid Sussex in South East England (39 per 100,000) Early deaths from heart and circulatory diseases (before the age of 75) are most common in the north of England, central Scotland and the south of Wales, and lowest in the south of England. Deaths from stroke and coronary heart disease deaths from stroke 1990-2010 Down by 12% in high income countries Up by 12% in low income countries  Recommendations of the Department of Health To change the percentage contribution towards the total Energy of the diet to: Total fat: 30-33 % of which, saturated fat: no more than 10% Protein: 10-15% Sucrose: no more than 10% (2014,5%) Alcohol: no more than 5%  Way forward Why do people choose to eat and drink what they do? Why do they choose a particular life style? How can they change?  Solutions? Education Clear labelling of food products Support and provision of facilities for the deprived groups of the population School food schemes Role models Control of advertising Pressure on food industry