What's a healthy serving size?

Grab any packaged food and there’s likely a nutrition label on the side that breaks down the nutrients per serving. This is usually listed per pack and also per serve, indicating sometimes that the item you’re holding may actually contain more than one serve. But, if you’ve ever noticed a small packet of chips that says three serves and then found yourself shocked by the tiny recommended serving size, you may realise that serving size doesn’t always reflect a realistic portion size. So, what’s the difference between a serving size and portion size, anyway? And does it even matter?

There’s definitely some confusion. Here, we unpack the facts and explain why it matters, what to look for and how to let a serving size guide you to enjoying a portion size that’s right for you, instead of the other way around.

Serving it up – the correct way!

Below are the recommended serve sizes set down by the Australian Dietary Guidelines, not manufacturers. Being mindful of these serve sizes will help you create healthier, balanced meals that are not too high in kilojoules, saturated fat and sugar.

Photography: iStock

Okay so... what is a serving size?

A serving size is often determined by the food manufacturer. “This might be decided to meet certain nutrition parameters, but it doesn’t often reflect what you actually eat,” explains dietitian Brooke Delfino. The Australian Dietary Guidelines state that a healthy serve of ‘discretionary’ food (ie sweet treats and salty snacks) is about 600kJ (140cals), so some manufacturers will use this to frame the serving size (irrespective of the pack size) to make their food appear healthier than it really is. That’s how a modest chip packet, which insists it contains three serves, can make the manufacturer seem responsible (and you irresponsible for hoovering through the lot).

Similarly, with powerful health messages these days urging people to reduce their intake of salt, sugar and saturated fat, sometimes a modest ‘serving size’ on food labels can make food appear healthier. For example, they may set the serving size to show that a food contains a healthy percentage of daily intake (%DI) for kilojoules and other nutrients. And if they want to meet the government requirement to list ‘low sodium’ on their packaging, they may manipulate the serving size to meet that number, giving them a ‘health halo’.

“We see this a lot in those seemingly healthy snack foods, like vegie chips and bliss balls, and even nut bars or oat-based slices,” says Delfino.

Just to make it even more confusing, an investigation by consumer advocate Choice found that, even with a single brand, serving sizes were inconsistent and varied on different-sized packs. But that’s not to say that all serving sizes should be ignored or are all bad. They do serve a purpose, especially for people who need to consider certain nutrients to help manage a health condition, like people with diabetes who dose insulin based on their carb intake, or someone struggling to get enough protein into their diet. Using the serving size can be a handy guide to help meet their nutritional needs.

“There are some food brands that have stepped up and are doing their part to help shoppers make better choices,” says Delfino. “Front-of-pack food labelling about what a serve is – especially on treat foods – is being adopted by some confectionery brands.”

So, if you’re confused, you’re not alone!

And what about a portion size?

A portion is the amount of a food you actually eat. So, if you pour a cup of muesli into your breakfast bowl, then that’s your breakfast portion. If you slice a chocolate cake into eight pieces for eight people, then that’s the portions.

Portion sizes at restaurants, takeaway outlets and in ‘junk’ foods have increased over the years. As an example, French fries and hamburgers are now two to five times larger than those originally served in the early days. According to the latest Australian Health Survey, a third of Aussies’ daily kilojoule intake now comes from such ‘discretionary foods’.

And much of what’s sometimes called ‘portion distortion’ is people obediently eating everything they’re served. “Serving sizes often give the impression that it’s the right amount of food to eat, which isn’t the case,” says dietitian Rachael Hartley, author of Gentle Nutrition.

Let’s face it, many of us grew up being scolded for not eating everything on our plate, so it’s no wonder we’re fallible when it comes to eating what’s put in front of us. And yet, in the same way our taste for certain foods can vary each day, so can our appetite and therefore the amount we should consume. Delfino agrees. “The portion size you eat will vary based on how hungry you are, how much activity you’re doing that day and also the time of day – if you’re eating a snack after dinner, it’ll probably be a smaller portion than if it’s 11am,” she says.

“So, while referring to the manufacturers’ serving size can be a starting guide, the best way to judge the right-sized portion to eat is to consider your own hunger level.” This can be tricky for some, so we show you a good place to start.

Finding the right amount of food for you

Dietitian Cara Harbstreet specialises in intuitive eating and explains that you can use a hunger-fullness scale to determine how much your portion size should be so that you’re full and satisfied with your food. This involves monitoring yourself as you eat and rating your hunger and satisfaction on a scale of one to 10.

Check in with yourself when you’re about halfway done before you keep going, Harbstreet says. Once you feel satisfied and comfortably full, whether that’s half a standardised serving or three servings, you can consider that your portion.

“Mindfulness and being attuned to your body are helpful skills to have when it comes to eating,” adds dietitian Alissa Rumsey, author of Unapologetic Eating. “Being able to understand what your body is asking of you and responding to it by feeding it what it wants and needs helps you to have a more pleasurable and satisfying eating experience.”

But, if you’re struggling to determine your hunger and fullness, Rumsey suggests that you focus on structuring your meals so they’re more regular (every four to five hours) and contain carbohydrates, protein and fats. A dietitian can also help you determine the best way to find your perfect portions.

Hartley adds that if you need extra guidance, when you’re plating yourself food, imagine you’re making a plate for someone else, she suggests. You likely can intuitively serve food better when you take yourself out of the equation.

If you’re not sure where to begin with finding the right portion size for you, the recommended serve sizes in the Australian Dietary Guidelines can have benefits, Harbstreet says, as long as you don’t let it become a tool for restrictions.

And when it comes to packaged foods, while the note on the pack isn’t gospel, Delfino says it can still be a helpful way of seeing if you’re currently serving up foods “in the general vicinity” of a healthy amount.

“A serving size of cereal will vary between brands from 30 to 45 grams (about half to one cup), and while that may sound confusing, in reality that small variation won’t make or break a healthy diet,” she says. “Try it at home – and if it turns out your usual bowl of cereal equates to three cups, then it might be more than what you actually need.” From here, let your intuitive hunger levels be your guide.

Snack attack

We know it’s incredibly hard to say no to that extra snack helping, but see if you can stick to these recommended portion sizes.

“We crave snack foods more than broccoli or salad because they have that rich salty, fatty and sweet mouth feel,” says Delfino. Curiously, in nature you won’t and all three tastes in the one food, yet manufacturers know that the trio is very moreish and addictive, which is why chips and biscuits are so easy to overeat.

A handy guide for snacks

Each of these portions below is about 600kJ (200cals), which is a sensible amount for a snack that’ll fit into a healthy diet – except for the glass of wine. Note: The kilojoule quantity is based on 250ml glassware for your reference – it’s important to remember that a standard drink is only about 100ml (355kJ/85 cals).