energy balance-getting it right
the UK department of health publishes dietary guidlines which are now dietary referance values (DRV's) which include:
- estimated average requirements (EAR).
- lower referance nutrient intake (LRNI).
- higher referance nutrient intake (HRNI).
these provide values which a healthy balanced diet should fall.
upper and lower limits have not been set for carbohydrates and fats, but instead for energy .
getting the balance wrong.
for good health we need both carbohydrates and fats.
to maintain the essential body processes we need a constant supply of energy.
the energy needed for these essential processes is called the basal metabolic rate (BMR) and varies between individuals. BMR is higher for
- fat people
- younger people
- more active people
more on energy balance
the 'average' person may require between 8000 and 10000 KJ per day but an athlete may require double this.
If you eat fewer kilojoules per day than you use, you have a negative energy balance. and energy stored in the body will be used to meet the demand.
a regular negative energy balance with result in weight loss.
If you routinely eat more energy than you use, you have a positive energy balance, the additional energy will be stored and you will put on weight.
defining overweight and obese
body mass index (BMI) is a way to classify someones weight relative to their height.
BMI = body mass (kg) / height 2 (M)
there is evidence that waist-to-hip ration is a better method than BMI and shows significant links to risk of heart attacks
consequences of obesity.
Obesity increases the risk of coronary heart disease and strokes .
the more excess fat you carry especially around your middle the greater the risk to you heart.
obesity can also increase the chances of type 2 diabetes which is referred to a non-insulin-dependent diabetes.
more consequences of obesity.
Obesity can also raise your blood pressure and elevate your blood lipid levels, which are both classic rick factors for cardiovascular disease.
studies suggest a positive correlation between saturated fat in the diet and high blood presssure also cardiovascular disease.