2.2: Nutrition Flashcards
Describe the Yalcoba, Cancun, Yucutan Mexico case study
Unusually stunted children and obese adults due to an influx of tourists and a tourists-tailored food market
At a global scale, how much of the human population is obese?
1/4
What do humans need for energy?
Fats
Carbs
Protein
What do humans need for growth and repair?
Protein
Minerals
Water
Vitamins
What do humans need for control of body processes?
Minerals
Water
Vitamins
What constitutes a ‘well-balanced’ diet?
10-25% protein
20-35% fats
45-65% carbohydrates
What is the most abundant nutrient in the human body and what is it used for?
Protein is most abundant in body
Cells are partially composed of protein
Protein is used for repair and growth (small intestine mucosa, red blood cells, collagen - bones)
Essential and non-essential amino acids
Protein is used for energy when carbs and fats are low
How much protein do adults need?
Around 50g per day
11kg in their body
How much protein do newborn children need?
5x the amount an adult needs (for growth)
Around 250g per day
Give 4 examples of different nutritional environmental stresses and their different dietary adaptations
- Inuit high fat diet in cold barren land of Greenland
- Kung san in the Kalahari desert have rich diet of nuts, tubers, berries
- Mbuti Pygmies in the Democratic Republic of Congo reside in rainforests with a lot of vegetative growth that isn’t that nutritious, therefore they find fruit and nuts and trade with local agriculturalists from around the forests
- Pastoralists concentrate on milk and cattle milk; they have lactase persistence
State 3 types of agriculture
- Slash and burn
- Floodplain rice subsistence strategy
- Industrial agriculture
Demographic transitions
Shifts in population size and age composition
Epidemiological transitions
Shifts in disease patterns
What is the nutrition transition?
Shifts in dietary and physical activity patterns due to shifts in the composition/behaviour of society, which are expressed in changes in nutritional outcomes (average stature and body composition)
Made up of 5 nutrition periods/patterns/historical developments in the history of humans
Each pattern was dominant to its period, but can still exist in other periods
What are the 5 stages of the nutrition transition?
- Collecting food (hunter-gatherers)
- Famine (settlements begin)
- Receding famine (industrialisation)
- Nutrition-related non-communicable disease (NR-NCD)
- Behavioural change
How can the first stage of the nutrition transition be characterised?
Collecting food (hunter-gatherers): High prevalence undernutrition Consumption of starchy staples Labour intensive Lean & robust High disease rate Low fertility Low life expectancy
How can the second stage of the nutrition transition be characterised?
Famine (settlements begin): High prevalence undernutrition Consumption of starchy staples Labour intensive Nutritional deficiencies emerge Stature declines High fertility Low life expectancy
How can the third stage of the nutrition transition be characterised?
Receding famine (industrialisation): Consumption of starchy staples becomes less important Low-fat intake High-fibre intake Limited fruits and vegetables Increased animal protein intake Labour intensive Weaning disease Stunting Slow mortality decline
How can the fourth stage of the nutrition transition be characterised?
Nutrition-related non-communicable disease (NR-NCD) High-fat diet High-cholesterol diet High-sugar diet Refined carbohydrates Low polyunsaturated fatty acids Low fibre Increasingly sedentary life Increased prevalence of obesity Contributes to degenerative diseases Accelerated life expectancy
How can the fifth stage of the nutrition transition be characterised?
Behavioural change Reduced fat Increased fruit and vegetables Increased CHO Increased Fibre Increased water Reduce caloric beverage intake Purposefully replace sedentarianism with active recreation Reduced body fatness Improved bone health Reduced NR-NCD Extended health aging
Which particular transition does the term ‘nutrition transition’ often reference, and why?
Transition from pattern 3 to 4
Because the concern about this period is very high; it affects lower and middle-income transitional countries; the diet shift is more dramatic in urban areas compared with rural areas, and happens more rapidly in the poor areas of the world
Explain 4 criticisms of nutrition transition model
- Nutrition transition model is accurate but does not capture all complexities of the effect of globalisation on diet; for example, depending on economic status, globalisation may create homogenization towards unhealthy diets or healthy diets – therefore homogenization and differentiation of dietary patterns occur simultaneously
- This scale doesn’t describe the environmental stresses, which are varied across the planet, therefore humans are at different stages across the planet
- Stages overlap periods, some early stages still dominate less developed geographic and socio-economic populations
- Its just a broad understanding, cannot be used to develop hypotheses because it is not nuanced enough to describe human dietary shift overall
How is undernutrition measured?
Measuring food intake using food diaries and recall
BMI
This is difficult to measure in a short time, so measurements are small scale rather than a broad overview
What are the 3 indicators of undernutrition?
- Underweight (for your age)
- Stunted (height for age) – sign of malnutrition in early years of life
- Wasted (weight for height and MUAC) – sign of acute short term malnutrition
What are the 2 conflicting views on where average nutrition measurement should lie?
- Fixed genetic potential view – average is worldwide
2. Individual adaptability view – average is environmentally/socially/individually determined
Why do nutrition studies focus on children?
Children require more protein for maintenance and growth, and there is a higher incidence of infection if a child is malnourished
What is the name of the scale used to determine mild/moderate to severe undernurtrition?
Protein energy malnutrition (PEM)/Gross Food Deficiency spectrum
What are the 3 short term consequences and 3 long term consequences of mild/moderate protein energy malnutrition (PEM)?
Short term:
Slower growth
Smaller body size
Late menarche
Long term:
Higher mortality risk
Higher morbidity
Cost to educational attainment and economic status
What are the consequences of severe protein energy malnutrition (PEM) in Kwashiokor?
Sudden weaning of children due to infectious disease
No easily treatable
What are the consequences of severe protein energy malnutrition (PEM) in Marasmus?
Children born prematurely due to maternal malnutrition
Children not breastfed
Treatable if caught in time
What are the four main symptoms that can arise from child malnutrition?
- Stunting
- Wasting
- Underweight
- Overweight
What are the consequences of 5 specific nutrient deficiencies?
Vitamin A → night blindness Vitamin C → scurvy Vitamin D → rickets Iron → anaemia Iodine → goitre
Overnutrition
Oversupply of nutrients, exceeding amount required for growth, development and metabolism, resulting in obesity and overweight
How many deaths did overnutrition cause in 2010?
3.4 million deaths
State the 3 methods of measuring overnutrition
- BMI
- Waist circumference
- Skinfold thickness
Between 1980 and 2013, how much did overweight and obesity rise?
Adults 27.5%
Children 47.1%
Since 2006, has increase in adult obesity in developed countries slowed down or sped up?
Slowed down
Where is overnutrition prevalent?
Under 5’s in Eastern Europe and Central Asia, Middle East and North Africa have high overnutrition rates
USA are world leaders in obesity, Mexico is close behind
UK among worst in Western Europe for overweight and obese people; obesity has more than doubled in the last few years; people with lower socio-economic status have higher levels of overnutrition (this is the opposition in other more underdeveloped countries)
What are the consequences of overnutrition in childhood? (6)
- Obesity
- Premature death in adulthood
- Insulin resistance
- Breathing difficulties
- Hypertension
- Psychological effects
Key trends in obesity: social class
Industrialised countries – obesity is inversely related to social class Developing countries – the converse
Key trends in obesity: minority groups/ethnicity
Higher obesity in some minority groups
Key trends in obesity: gender
Men plateau earlier
Presence of high risk periods for women (pregnancy, menopause)
For gender, it varies by country/region
Key trends in obesity: children
Higher prevalence of obesity in children
Major risk factor for being overweight in adulthood
What are the 5 main consequences of obesity?
- Ineffective circulatory system – strain on heart, CVD
- Ineffective metabolism – type 2 diabetes, gout/gallstones
- Increased risk of cancers
- Mechanical consequences – obstructive sleep apnea
- Emotional disturbance – low self esteem, depression
In which 2 ways has globalisation affected our nutrition?
- Food and energy intake
2. Physical inactivity
How had globalisation affected food and energy intake?
Changes in global food system driven by market economies & consumption-based growth
Nutrition transition – move from complex carbs to sugars and fats, diet decreased in diversity
Food is more processed, energy-dense, affordable, effectively marketed
Local food is more expensive and therefore a choice for the affluent
How has globalisation created physical inactivity?
Urbanisation
Mechanised transport
Labour saving technology
Adults are less active in the workplace due to information & service based economies
Children receive less physical education at school, walk less, have more screen time
What do acculturation/migrant studies show about how migrant nutrition is affected by globalisation? (4)
- Generational differences in food preferences
- Increase in wage employment for women, but low income with demanding work schedule – lack of time to prepare food and lack of money for good, diverse food
- Re-invention of local ‘traditional’ foods in new country
- Food as ‘instant gratification’
Obsogenic environments
An environment that promotes gaining weight (diet and lifestyle) and is not conductive to weight loss within the home or workplace
Describe how genetic factors at an individual level could incur obesity. Give examples.
Single gene disorders incur obesity
E.g. Prader-Willi Syndrome arises when the paternal segment of chromosome 15 is deleted; it causes upper boy obesity, short stature, and intellectual disability
Susceptibility genes increase an individuals susceptibility to becoming obese
E.g. the FTO gene is involved in appetite regulation (leptin is a hormone that regulates energy balance by inhibiting/causing hunger) and thermodynamic regulation
What is the thrifty genotype hypothesis and how is it linked to obesity?
Obesity was adaptive and enabled survival through periods of famine; in the modern world these genes make individuals more susceptible to obesity
Critique the thrifty genotype theory
No one has found the gene that suggests obesity was adaptive
The theory suggests there were periods of feast and famine, but there is no evidence of this
Suggest 2 ways in which obesity could have genetically evolved (aside from the thrifty genotype and thrifty phenotype hypotheses)
- Obesity is a maladaptive by-product of positive selection on another traits, such as brown adipose tissue thermogenesis
- Drifty gene hypothesis – obesity genes are neutral and drift over evolutionary time
What is the thrifty phenotype hypothesis and how is it linked to obesity?
Mismatch between environment in early life (when developmental plasticity is higher) and environment during development in later life can cause obesity if the environment transitions from more stressful to more affluent
Explain how health and disease could have origins in early development
Nutritional disturbance and environmental chemicals could effect development due to the plasticity of the epigenome, causing long term effects on gene expression and increased risk of disease
What should the policy responses to obesity be? Describe 3 responses.
- Policy interventions in economic systems, food supply an marketing, and recreational behaviour
- Health promotion programmes and social marketing to change health behaviour (food consumption and activity levels)
- Drugs, surgery to lower energy intake
Environment of evolutionary adaptedness (EAA)
An environment you are adapted to, for example, it is argued that humans are adapted to the hunter-gatherer lifestyle and palaeolithic diet
Evo-deviatonary
Development to the environment of evolutionary adaptedness (EAA), which can result in non-communicable disease
What is the problem with BMI as a measurement?
Doesn’t actually measure the amount of fat in the body, so someone with high BMI could just have high muscle mass
Obese
When body weight is 20% above average weight
Underweight
When body weight is 15-20% under average weight
