So why do we need food? It may seem obvious to live, but it's alot deeper than that and i think it is important to know if you are trying to keep fit. After reading this post you will be able to look in your cupboards and say "right i need that", you'd be surprised if you went through your cupboards and picked out the foods that you actually need, and how much would be left that isn't needed, we call these 'snacks' nothing wrong with them but too many can lead to obesity and then from that to life threatening diseases. (and when i say snacks i think you know what i mean :))
Believe it or not some fats are good for us! When we hear the term fat we usually assosiate it with obesity, weight, we never assosiate it with healthy terms. Some fats are vital for healthy bodily functions, but why? Well fats are mainly found in things like meat, fish, and plants and we need fats because they play an important part of making all cell membranes and play a vital role in absorbing fat-soluble vitamins (A,D,E, and K). Fat gives us body insulation and also acts as a source of energy.
That is only one of the reasons we need food, but other reasons involve minerals, vitamins, salts, sugars, these all come from foods.
So a topic that i think i need to go into with depth is energy! I've spoken alot about energy in the past posts but that is because it is so important to balance energy with the amount of exercise you do! Anyway we can calculate our energy requirements! Yes we can, this is an essential tool in my opinion. Our requirements depend on alot of factors such as age, gender, whether we are still growing, pregnancy, menstruation and much more. Basal metabolic rate (BMR) is a measure of how much energy you need for essential functions like breathing and heart rate. BMR is highest in younger people and starts to decrease after the age of 10. Because of greater muscle mass, men generally have a higher BMR, therefore men must intake a higher amount of calories than woman. Following so far? Elderly people have a decline in muscle mass so they tend to need less calories than the younger generation.
A few examples of maintenance calorie requirements for different activities for adults are listed below:
- Sedentary or bedbound people:11.5cal per 450g (1lb) of body weight per day.
- People who only do light activities:13.5cal per 450g (1lb) of body weight per day.
- People doing moderate activities:16cal per 450g (1lb) of body weight per day.
- People doing vigorous exercise such as athletes or manual laborers or patients recovering from injury:18cal per 450g (1lb) of body weight per day.
How we get nutriets....
Take a look at what you eat on an average day and you will probably see a variety of foods from all food groups. You probably get a wide range of nutrients from the five different food groups. This is what your nutrient intake is all about.
The energy you obtain from food is measured in calories. However since one calorie is almost nothing we tend to speak in kilocalorie (kcal). 1 kcal = 1000 cal. Also you may see the term kilojoules (kj) this is another way of measuring energy and can be sometimes seen on the food label next to the caloric value. 1kcal = 4.184kj. So you can see energy can be quite complicated at times and sometimes annoying to understand i wouldn't blame you if you read over this paragraph once or twince to understand.
Each type of nutrient produces a certain amount of energy:
- 100g protein:400cal
- 100g carbohydrates:400cal
- 100g fat:900cal
Please feel free to ask any questions on this topic by leaving a comment after this post!
Thank you!
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