Last week we learnt how to control calories out. This is done by increasing our Base Metabolic Rate (BMR) and exercising.  Lean Body Mass (LBM), i.e more muscle, helps to increase our BMR which in turn helps us to burn more energy at rest and during activity.


We also learnt that the average person requires 8700 kj per day (~2000 calories) for normal activities of daily living.


But what happens when we play around with how many kilojoules we consume?  That is, the quantity of our food.


If we consistently eat just over 8700 kj every day, we will gradually gain weight over time.

If we consistently eat just under 8700 kj every day, we will gradually lose weight over time.


The same rule applies when we consider the quality of the food we eat. For example, if we ate just over 8700 kj of only fruit and vegetables, we would still gain weight over time.

If we ate just under 8700 kj of fast food and sweets, we would still lose weight.


However, if we consistently eat an unhealthy diet, the negative effects will show in other areas of our health. In the short term, poor quality nutrition can contribute to stress, tiredness and decreased capacity to work. In the long term, it increases the risk of developing major health problems, such as high blood pressure, high cholesterol, heart disease, stroke, type-2 diabetes, osteoporosis and depression.


Weight management is about eating the required number of kilojoules for your level of activity- no more and no less. For example, someone who exercises at a very high intensity can consume 2.0 x 8700 kj, whereas someone who exercises mildly should only consume 1.25 x 8700 kj.



To optimise bodily functioning, our 8700 kj need to include all the essential nutrients we need for optimal functioning. The best way to get all the nutrients you need is to eat a variety of food from the five food groups.

Five Food Groups Recommended average daily number of serves
Vegetables and legumes/beans 5
Fruit 2
Lean meats and poultry, fish, eggs, tofu, and nuts 4-6
Grains, mostly wholegrains. 2-3
Milk, yoghurt and cheese 2.5-4


To determine specific recommended number of serves for your age and gender, follow this link.


Stay tuned for next week to learn about the importance of balance in managing weight.