Nutrition And Excercise Flashcards
What is nutrition?
The WHO defines it as the intake of good considered in relation to the body’s dietary needs (ie the body has what it needs and when it needs it).
What is malnutrition?
The NHS defines it as a serious condition that occurs when a person’s diet doesn’t contain the right amount of nutrients (e.g. undernutrition or overnutrition).
What are the global impacts of malnutrition?
1) Obesity contributes to around 4 million global deaths annually and global obesity has doubled since 1980.
2) Undernutrition explains around 45% of deaths in children under 5 and stunts the growth of around 20% of this age category.
3) Combined, this costs societies around the world $4 trillion a year.
How does nutrition impact individuals?
1) Appropriate nutrition can boost memory and help to maintain cognitive function during ageing (e.g. omega 3 fatty acids in foods, such as oily fish and nuts, are linked to lower levels of beta-amyloid protein implicated in the development of Alzheimer’s dementia).
2) Several research studies show a link between good dietary quality and a lower risk of depression.
3) Almost half of deaths caused by heart disease, stroke and type 2 diabetes, in America, are linked to poor diet, with high consumption of processed meat and sugary drinks.
4) Poor diets are associated with 80,000 deaths from cancer in the US each year.
What are the wider impacts of nutrition?
1) Global warming: food systems are responsible for more than 25% of or greenhouse gas emissions, more than the entire global transportation sector.
2) Antibiotic resistance: huge quantities of antibiotics are used in meat production, but instead of treating illness, they are often used to promote growth and prevent disease, resulting in some nations using 4x more antibiotics in animals than in humans. This leads to antibiotics resistance in bacteria, causing severe health consequences for both humans and animals.
3) Animal welfare: modern farming methods leads to ethical concerns regarding animal welfare as they cause unnecessary suffering.
What are the 2 large categories of nutrients in food?
1) Macronutrients: these are needed in large amounts and provide the body with energy, as well as fulfilling other vital bodily functions such as body growth and repair. There are 3 major causes she’s of macronutrients:
> Fat - divided into 3 categories:
* Unsaturated fats are mainly found in food from plants, such as olive oil, and fish. There are 2 types: mono and polyunsaturated. They’re good for health as they reduce inflammation and lower cholesterol.
* Saturated fats are mainly found in meat and dairy products. Research about saturated fats is evolving and often contradictory, but current advise is that reducing saturated fat can be good for health, if they are replaced by unsaturated fats.
* Trans fats are mostly artificial and are produced by eating vegetable oil in the presence of hydrogen. This increases their stability and shelf life, meaning that they’re often used in processed and fast food. They are very dangerous to health as they increase inflammation, increase insulin resistance and raise the damaging low density lipoprotein cholesterol.
> Carbohydrate - divided into 2 broad groups:
* Simple carbohydrates are sugars that can either be monosaccharides or disaccharides.
* Complex carbohydrates (e.g. starch) can either be oligosaccharides or polysaccharides, meaning that they have 3 or more saccharides in their chain. Examples include pasta and rice.
* Fibre is also an important type of carbohydrate. The body cannot digest fibres, although it can sometimes be fermented by microorganisms in the gut. This means that it has several crucial functions, including: hunger regulation by its bulking properties, glucose regulation by delaying gastric emptying which slows sugar absorption, the movement of food through the gut to ensure regulate bowel movements. These properties help reduce the risk of illnesses such as colon cancer, type 2 diabetes and heart disease.
> Protein - a key component of every cell in the body and essential for growth and repair. They are also the building blocks of enzymes which catalyse almost all metabolic reactions. They are formed from amino acids, some of which can be made by the body, but 9 of them - the essential amino acids - must be absorbed from food. Protein sources include meats and plants (e.g. legumes, nuts, seeds and whole grains).
2) Micronutrients: these are only required in very small amounts, but should not be underestimated so deficiency has severe consequences, including death. Essential micronutrients are those that the body can’t manufacture and must be absorbed through diet. There are 2 types of micronutrients:
> Vitamins
> Minerals
Sailors throughout history have suffered from scurvy, due to vitamin C deficiency. Vitamin D is essential for good bone health. Folate and iodine are essential for healthy foetal development. Iron is essential for blood production. Vitamin A plays an important role in eye sight and its deficiency is the leading cause of preventable blindness in children.
Outline the importance of water in nutrition
Although neither a macronutrient or micronutrient, water accounts for 60% of the human body weight and is essential for vital bodily functions, such as temperature and weight regulation.
What is the Eatwell Guide?
This was an objective guide developed using the best scientific evidence available. It uses the analogy of a plate and contains 4 major food types:
1) Fruits and vegetables: vital in providing humans with fibre and micronutrients, as well as carbohydrates and in some cases, unsaturated fats. Humans should aim to each a minimum of 5 portion of different fruits and vegetables each day. Research conducted at Imperial, suggests that up to 10 portions a day can reduce the risk of serious diseases even further. 2) Starchy carbohydrates: these are an important energy source, making up around 1/3 of the food eaten by humans. Ideally, this would be composed of mostly whole grains (e.g. whole wheat pasta and brown rice), as they contain vital fibres and micronutrients from the bran, which is lost during the processing of non-whole grain carbohydrates. 3) Protein: found in fish, eggs, meat and pulses. The Eatwell Guide suggests that most protein come from pulses, a category which includes: beans, lentils and peas. 2 portions of sustainably sourced fish, should also be eaten every week, one of which should be oily (e.g. salmon or mackerel) so as to get healthy unsaturated fats, such as omega 3. Less red meat should be eaten, particularly processed forms such as sausage and bacon and reducing its consumption has a positive impact on the environment. 4) Dairy: this includes milk, cheese and yogurts, which provide calcium, essential for healthy bones, proteins and some vitamins.
The guide advises consuming low fat and low sugar products and using plaint oils contains unsaturated fats (e.g. olive oil), which have many benefits but a high calorie content. Humans should also aim to drink 6-8 glasses of water/milk/sugar free drinks per day. Limit consumption of highly refined sugar foods such as sweets, cakes and muffins. All of the food sources on the Eatwell Guide, combined, give a recommended average daily energy intake of 2000 calories for woken and 2500 calories for me, but this varies based on factors such as activity levels and general health.
What is a food desert?
This is an area that has limited access to affordable and nutritious food. In the UK these have been defined as neighbourhoods of between 5,000-15,000 people served by two or fewer big supermarkets. Instead, they are often served by small, reasonably expensive convenience stores, or takeaways. They disproportionately effect the poor, elderly or disabled, who either cannot afford to travel longer distances to supermarkets or are physically unable to. This can compound inequality and socioeconomic disadvantage.
Outline the impact of physical inactivity
Physical inactivity, linked to poor walkability and lack of access to recreational areas, accounts for an estimated 3.3% of global deaths (WHO, 2011). In England today, only 60% of adults do enough physical activity to maintain good health.
What is primary prevention?
This is the way in which disease is prevented from occurring. For instance, physical activity reduces the risk of developing many of the non-communicable diseases that are so prevalent in society today, it is also important in improving outcomes of existing disease and preventing them from worsening.
What is physical activity?
It is defined as any bodily movement produced by skeletal muscle that requires energy expenditure, meaning that it can include activities such as walking and gardening.
What are the 4 categories of physical activity?
1) Aerobic
2) Strength
3) Flexibility
4) Balance
What are the 5 different intensities of physical activity?
1) Sedentary - not moving (e.g. working at a desk)
2) Light - cleaning, farting out rubbish, yoga
3) Moderate - walking, cycling, shopping (requires 3-6x MET, more energy than sedentary activity). Patients should be able to talk but not sing, for instance.
4) Vigorous - football, dancing, swimming (requires >6x MET, more energy than sedentary activity). Patients should find it difficult to maintain conversation.
5) Very vigorous - sprinting up hills, weight exercise, press ups
Outline the impact of physical activity on the neurological system
1) Regulation of physiological response via somatic and autonomic (sympathetic and parasympathetic) nervous systems
2) Increased production and release of monoamine neurotransmitters (noradrenaline, serotonin, dopamine, etc).
3) Cerebral blood flow and oxygen supply maintained
