Fat Percentages Explained

Percentage of Energy from Fats

While health authorities recommend a maximum of 30% of your total energy intake (calories/kilojoules) should come from fat, it isn’t implied nor recommended that you eat only foods with less than 30% energy from fat.

Your normal diet is made up of foods which are either well above or below 30%. You should only aim for each meal or your total day’s eating to be made up of less than 30% energy from fat.

Some higher fat foods such as avocados, nuts and seeds, are highly nutritious and favour lower blood cholesterol levels. Moderation is the aim – not elimination.

Regardless, knowing the percentage of energy from fat in foods can be useful in spotting high-fat foods and drinks.

Formula for Calculating Percentage Energy from Fat:

Grams of Fat/Serve x 9

Total Calories/Serve

X 100


Grams of Fat/Serve x 37

Total Kilojoules/Serve

X 100



Mars Bar (11g fat, 265 cals)

Percentage calories from fat

= 11 x 9


X 100


= 37%

Percent Fat Contents In Food

Don’t be fooled by marketing claims of foods showing a low percentage of fat. It’s serving size and total grams of fat that count.

For example, whole milk containing 3.8% fat sounds low (3.8g fat/100ml), but a 250ml cup contains 9.5g fat (and 2 cups contain 19g fat). Given the amount you’re likely to consume in one sitting, this could be a higher fat choice than it originally seemed.

Ice cream containing 10% fat seems high, yet a large scoop (50g) has only 5g fat. (Low-fat ice cream has less than 2g fat/serve.)

Note: The percentage of fat in a food is not the same as the percentage of calories or kilojoules derived from fat. Foods with a low percentage of fat can still have a high percentage of energy derived from fat – as shown below.

For example, around 50% of total energy in whole milk comes from fat – yet whole milk has less than 4% fat. Low-fat milk with less than 1% fat contains only 20% of total energy from fat – a far better choice.

Calculating the Amount of Fat Corresponding to a Set Percentage of Calories from Fat


An active person who consumes 3,000 calories per day (12,540 kilojoules) wishes to calculate the amount of fat corresponding to 30% fat calories.

  1. Calculate 30% of 3,000 calories
  2. = 900 fat calories.
  3. Divide by 9 since each gram fat supplies 9 calories.
  4. = 100 grams fat.

Fat Content & Percentages in Milk









Percentage Fat 3.8% 2% 1% 0%
Fat (Grams) in 250ml Cup 9.5g 5g 2.5g 0g
Calories (Kilojoules) 167 (700) 125 (525) 115 (480) 88 (365)
Percent Energy

(Cals/kJ) From Fat

51% 36% 20% 0%

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