Why does the WHO give sugar recommendations in terms of percentage of energy intake?

Question

The WHO recommends that less than 10% of our "total energy intake" be due to free sugar. From the cited report:

Total energy intake is the sum of all daily calories/kilojoules consumed from food and drink. Energy comes from macronutrients, such as fat (9 kcal/37.7 kJ per gram), carbohydrate (4 kcal/16.7 kJ per gram) including total sugars (free sugars + intrinsic sugars + milk sugars) and dietary fibre, protein (4 kcal/16.7 kJ per gram) and ethanol (i.e. alcohol) (7 kcal/29.3 kJ per gram). Total energy intake is calculated by multiplying these energy factors by the number of grams of each type of food and drink consumed and then adding all values together.

Doesn't this technically mean that it's okay for me to eat huge amounts of sugar as long as I also eat a ten plates of pasta a day, or something? What is the rationale for using this metric, and how do I know that I'm eating a healthy amount of sugar because I'm eating low sugar, and not because I'm just eating more non-sugar calories than I should be?

Answer 1

You're overthinking it.

All they are saying is that they strongly recommend no more than 10% of total daily calorie intake be in the form of sugars, and they conditionally recommend that no more than 5% be the goal.

So, if your daily caloric intake goal is 2000 calories, they recommend no more than 200 calories come from sugars. Adjust for your own caloric needs. (Just as a note, many food labels in the United States assume a 2000 calorie diet for their serving size/dietary information panels. Most will tell you the calorie amount they are basing it on.)

Technically, yes, if you eat 10,000 calories in a day, you could have 1,000 calories of sugar. However, that much caloric intake would present problems of their own in short order (excepting highly active individuals whose training regimens dictate that level of intake).

Answer 2

Free sugars have no associated vitamins/minerals. They are, for all intents and purposes, nothing but calories/kilojoules. Yes, there is carbohydrate sugar in fruits, vegetables, grains, pulses, legumes, dairy, basically everything, but a carrot/apple/slice of bread/etc has more in it than just its energy content.

Australia's Dietary Guidelines (eg, 'eat 5 serves of vegetables/day, 2 serves of fruit/day, etc.) are constructed based on currently understood empirical evidence such that 95% of the healthy population could consume it and experience the least amount of food-related chronic disease risk - which more or less translates to 'bare minimum to get the body's micro-nutrient needs without excessive calorie intake (and thus the associated weight gain and associated problems). I'm assuming most countries use a similar mindset. You can read the health educator guide or summary of scientific evidence publication here for a more detailed explanation of of why the decisions were made and based on what evidence (or look up your own country's guidelines or international bodies like the WHO).

If you're 'using up' your daily calorie limit on foods that are primarily energy (calories) with no associated micro-nutrients (eg. processed snack foods/drinks with loads of excess "free sugars"), you're missing an opportunity to meet your body's micro-nutrient needs without exceeding your daily calorie needs. That doesn't necessarily mean that you can't ever have junk food - Australia's dietary guidelines were formed with actual eating behaviors in mind (not just biochemical ideals), so the daily recommendations do allow for occasional discretionary (junk food) choices, because you need to be realistic about what the majority of the population is able to achieve.