The Obesity epidemic
To stay in optimum health, humans need to have a nutritional energy balance. That is for the energy going into our bodies through food (measured in kcal) should be balanced with the energy we expend (whether at rest or through physical activity).
If there is an energy deficit, not enough energy is going into the body to cover what we expend. The body uses energy/ fat reserves stored in our liver and muscles to redress the balance. If there is an energy excess, we are consuming more food than our bodies need. The excess is converted into fat and stored in adipose tissue under the skin.
There is an obesity epidemic; more people than ever before are creating an energy excess within their bodies. There are several reasons for this:
1) Evolution – during the Middle Palaeolithic era (200,000 years ago) humans needed to accumulate fat during the warmer months to ensure their bodies had the reserves needed to see them though the sparse winter months. Our intelligence has developed to create farms, increase food productivity and in the last 200 years to create food that is widely available to the masses throughout the year, however our bodies have not evolved to stop the inbuilt cravings for carbohydrate and fat rich food. Our diets no longer to follow the indulge now while you can summers/ become lean over winter path.
2) The foods we crave are available all year round, our diet is the same all year round. Graph 1* shows us that between 100 and 200 years ago sugar consumption slowly increased with the first records telling us under 10% of the population were obese. With the exception of the two world war periods from 1900 sugar consumption increased dramatically with a steady incline in the percentage of the obese population. From 1950 when work and lifestyle habits became more and more sedentary obesity prevalence dramatically increased. Graph 2* shows that in the last 30 years the average calorie intake in America has increased by 425 kcal (20%), this demonstrates that we are following our cravings more than we are our needs of hunger and nutrition. Graph 3* shows that in the last 40 years the percentage of linolenic acid(a polyunsaturated omega 6 essential fatty acid) has increased it’s presence in subcutaneous fat from 11% to 23%. Whilst in small amounts this essential fatty acid is needed for normal growth and development, in large amounts it can raise blood pressure and lead to blood clots, heart disease and strokes. Naturally linolenic acid is found in seeds and nuts, in our modern day diets these plants are used as vegetable oils, which in tun are used to cook convenience foods. With a higher reliance on these types of foods we see a higher incidence of the ‘bad’ fats in our body and a higher incidence of diet related illness.
3) While this is happening our lifestyles are becoming more sedentary with more of the population having moved from roaming lifestyles to farming lifestyles to office bound with long hours at work. Rewards are more often not to go for a long walk or daily gym sessions but sit in front of the television and consume more of the high fat foods that are advertised there.
Obesity has an affect on several layers;
1) For the individual there are long term health implications including an increased incidence of high blood pressure, heart disease, type 2 diabetes, high cholesterol and some cancers, all can lead to a shorter life.
2) For the economy obesity means a loss of productivity as a higher proportion of people have time off work due to obesity related illnesses.
3) The cost to the NHS increases year on year as they treat patients with obesity related illnes and death.
Preventative measures need to be put in place by the government which target the problem from multiple aspects including advertising, health at work, availability of types of food, access to fitness facilities and education.
made with reference to
Graph 1 Johnson, R.A. Et al Potential role of sugar (fructose) in the epidemic of hypertension, obesity and the metabolic syndrome, diabetes, kidney disease and cardivascular disease . The American Journal of American Nutrition 2007
Graph 2 Dr. Stephan Guyenet The American Diet 2012
Graph 3 Dr Stephan Gyuyenet Seed oils and body fatness – a problematic revisit Whole Health Source
Graph 4 shows the increase in percentages (male from 13% to 26% from 1993 to 2013)(women 17% to 24%)
Graph 4 Health survey for England 2014 Health and Social care information centre