Most of you will say that women should eat around 2000 calories a day, and men should eat around 2500 calories a day. This information is in fact very misleading and it’s no wonder many people are overweight - they are simply eating far too much. This commonly reported figure is an average figure. In fact, several parameters are required to access the true calorie requirement for an individual person including:
Age
Weight
Metabolism
Core body temperature - (a lot of overweight people do not have a body temperature of 37C linked to thyroid functioning)
Lean muscle mass (see last article)
Physical activity level
Climate
Dieting history
Eating habits
Calories are a measurement of energy and your body utilizes this energy to fuel your body so that it can function to stay alive. This energy is released during the metabolism of food.
The first component that determines your calorie requirements is your Basal Metabolic Rate (BMR). BMR is the number of calories required for your body to perform basic functions such as breathing, maintaining body temperature, and keeping the heart beating - basically, the amount of calories required if you were to lie in bed all day. This figure accounts for 60-75% of the total calories required.
Above is a link to a BMR calculator - and you can see how many calories your body required to function on a basic level.
20-30% of your calories are burnt through exercise and activity. This is the most variable factor in determining your calorie needs.
10% of your calories are burnt by the amount of heat generated by food eaten. Example, to digest and absorb a 100 calorie yoghurt, 10 calories are used simply to digest and absorb the nutrients.
So, at the end of the day, the majority of your calorie needs is determined by how fast or slow your metabolism is working. As I mentioned in the last article, the higher your muscle mass, the faster your metabolism, as muscle cells are 8 times more metabolically active than fat cells – so I cannot overemphasize the importance of high lean muscle mass!
Keeping a balanced diet will help maintain a suitable lean body mass, preventing loss of muscle tissue and also building muscle tissue up to a suitable level.
After we understand this, we need to understand WHAT we are putting into our bodies. Are these calories feeding us nutritiously or are they merely empty calories that provide no nutrients and leave us feeling hungry and dissatisfied? Learning to read a nutritional label correctly is a skill that everyone should learn to maximise their health.
Next check how the label analyses the contents by looking at the serving size. They will either give a suggested serving size (misleading) or per 100g. Serving size can be misleading as it may be ½, ¼ or any percentage of the total amount of the item. In this case the serving size is assuming you eat the entire bar and is 1 serving.
Check the number of calories. Calories can be listed as Kcal, Cal (same thing as kCal) or Kj (kilojoules). To convert Kj to calories, divide by 4.2.
Low calorie food: 40 calories or less
Moderate calorie food: 100 calories
High calorie food: 400 calories or more
Each meal should contain between 20-25% of your total calorie requirement for the day
Example: On a 1700 calorie requirement:
Breakfast, Lunch, Dinner should each contain between: 340-420 calories (20-25% of 1700 Cal)
Snacks (20-25%): If you eat 2 snacks per day, make sure the combined snacks equal this percentage. Aim for no more than 200 calories per snack.
Check the total carbohydrates, sugars, protein, total fat, saturated fat, trans fat, cholesterol, sodium and fibre.
Check the total carbohydrates, sugars, protein, total fat, saturated fat, trans fat, cholesterol, sodium and fibre.
Carbohydrates appear in food as starch, sugars or fibre. Sugar can either occur naturally in the food or can be added to the food for taste. Note only added sugar is listed on the labels ingredients, however the total sugar is accounted for on the nutritional label. The minimum amount of glucose (simple carbohydrate sugar) required for the brain to function is 130g per day. Carbohydrates should account for between 40-60% of calories consumed. So...calculation time:
If your BMR is 1600 calories per day, eating 50% of your calories as carbohydrates means:
If your BMR is 1600 calories per day, eating 50% of your calories as carbohydrates means:
(1600/100) x 50% = 800 calories from carbohydrates
To calculate how many grams of carbohydrates this is, divide by 4 (as 1g of carbohydrate = 4 calories)
800/4 = 200g carbohydrates.
Nutritional labels will tell you how many grams of carbohydrates are in the food, so make sure the sum of your meals is 200g of carbohydrates or less. Sugar from carbohydrates should not exceed more than 10% of your calorie intake. Recommended sugar allowances range from 6-10%. Based on a 1700 calorie diet:
(1700/100) x 6% = 102 calories
102 calories/ 4 = 25.5g
(1700/100) x 10% = 170 calories
170/4 = 42.5g
(Maintain between 25.5-42.5g sugar per day) - Assuming you eat this chocolate, you have already eaten 21g of sugar! Half your sugar allowance for the whole day!
(Maintain between 25.5-42.5g sugar per day) - Assuming you eat this chocolate, you have already eaten 21g of sugar! Half your sugar allowance for the whole day!
This in fact is a low figure, and many people far exceed this. Avoid sugary cereals, cereal bars (loaded with sugar), fruit juice (sugar sugar sugar and no fibre!), ice cream, pastries, cakes etc.
Proteins make up muscle and other tissue and are also the basis for enzymes, hormones and many factors that fight infection. Protein should constitute between 15-30% of calories consumed. Ideally, your protein should not be less than 20%. Personally, I recommend protein intake should always be kept on the upper end limit to ensure high muscle mass and high metabolism (25-30%).
Hence based on a 1700 calorie diet,
425-510 calories must come from protein. (25-30%)
To determine the number of grams of protein, divide by 4 (1g protein = 4 calories).
=106.25g-127g.
There is another way to assess protein needs based on body weight:
According to the US RDA, a sedentary (inactive) person should get 0.8g of protein per kg body weight.
Example: 60kg woman (no exercise) should consume (60 x 0.8) = 48g protein
Those who exercise need to increase this amount to 1.2-1.8g per kg body weight:
60 x 1.2 = 72g
60 x 1.8 = 108g
Using this method, you should consume between 48-108g protein per day. I prefer to use the previous calculation based on calorie needs (106.25-127g), as calorie needs have assessed your metabolic rate (BMR) including height and weight. The latter method only accounts for body weight.
Fat on nutritional labels is reported as Total Fat and subdivided into: saturated fat (bad), unsaturated fat (good), trans fat (very bad) and cholesterol.
Fat is needed to help the body utilise some vitamins, provide healthy skin and importantly provide a “full” feeling after meals. The recommended fat intake is 30% of calories consumed. I recommend that this value stay fixed – I don’t agree with low fat diets (unless there is serious cholesterol problems or heart disease/diabetes) because these low fat diets often cause chronic hunger, meaning you are more likely to consume too many carbohydrates – which ultimately get converted and stored as fat anyway. Secondly, good fats are needed for proper brain function, and finally low fat foods often contain a much higher sugar content (to make it more palatable) than full fat options.
Fat provides more calories than carbohydrates or protein and is calculated differently.
Assuming a 1700 calorie diet:
(1700/100) x 30% = 510 calories from fat per day
1g fat = 9 calories
510 calories/9 = 56.6g fat per day
When looking at nutritional labels, the lower the saturated fat content, the better! Make sure that your saturated fat does not exceed 10% of your calorie limit. For a 1700 calorie limit, this would be
(1700/100) x 10= 170 calories
170 calories/9 = 18.8g saturated fat per day
The chocolate above has 7g of saturated fat - almost half the daily limit! Eating other foods high in saturated fat (chips, cheese, cake, muffins, butter, ice cream, red meat) will push you over your limit for the day.
Cholesterol should be limited to 300mg per day. Those suffering from heart disease and related problems should keep cholesterol as low as possible. Trans fat should be kept as close to 0g as possible. If you see trans fat on a label, avoid!
Fibre must be at least 25g-30g per day. Anything over 3g of fibre per serving is good. A small apple contains about 2.9g of fibre, medium nectarines 2.4g and a medium banana about 3.1g, slice of brown seeded bread 2.9g, 40g serving Hi-fibre bran 9g.
Finally check the other nutrients – Avoid high salt levels – the old upper limit for salt intake was 2300mg per day, however now is as low as 1500mg per day. Those with heart disease must not consume more than 1200mg sodium per day. Make sure you get enough vitamins and minerals –
Calcium – at least 1000mg per day.
Vitamin C – RDA recommends a minimum of 75mg per day. I recommend not less than 500mg per day, with an upper limit of 2000mg per day. Cancer patients have found beneficial results using 10 000 – 20 000mg vitamin C per day (proven scientifically).
Iron – males 8mg per day, and females 18mg per day. Those with low iron levels must increase more than this amount.
Vitamin A – Minimum 5000IU per day.
Avoid preservatives, chemicals, AVOID MSG (this is linked to obesity in many clinical trials ), avoid high fructose corn syrup (linked to diabetes- I personally have done research on this in the laboratory and found severe effects).
In a nutshell my advice is:
Eat fruit and/or vegetables every day.
Get enough protein - there are options for vegetarians to ensure they get enough discussed in an article to come.
Avoid sugary foods
Get enough fibre
Eat small meals every 2.5-3 hours (stabilises blood sugar, insulin levels, prevents overeating and unnecessary snacking)
Drink lots of water (avoid/minimize fruit juices, coffee, alcohol)
Enjoy a little indulgence - there is no need to fully cut anything from your diet but, everything in moderation, and if on occasion not moderation, then make a compensation!
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Its not that hard to be healthy, if you pay attention to what you're doing.
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