Supermarket diet foods

We talk to the experts about popular diet brands and whether they can really help you lose weight.
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02.Counting kilojoules

How many kilojoules should you have?

Dieters should eat no less than 5000kJ a day, otherwise you run the risk of missing out on the nutrients you need and end up starving and unhappy
- Dr Joanna McMillan

“Dieters should eat no less than 5000kJ a day, otherwise you run the risk of missing out on the nutrients you need and end up starving and unhappy” says McMillan. “A main meal should be about 2000kJ and a snack 600kJ.

The Coles Simply Less website offers some sensible weight-loss tips, but its daily meal plans are high in Coles packaged products and low on fresh fruit and veggies. The main meals are very low kilojoule (dinner 1477kJ), and on one day of the plan almost one-third of the kilojoules were made up of snacks or desserts such as chips, custard and brownies.

“Although you’ll lose weight on a strict diet of low-kilojoule products in the short term, it’s not sustainable,” says McMillan. “To keep weight off, you’re better off joining a program and/or working with a dietitian to learn how to eat to maintain weight in a healthy way.”

Portion perfection

“If you consistently shave 600kJ off your daily kilojoule intake and exercise, you’ll lose weight over time,” says Funder. Eating smaller portions is one way to achieve this.

A study published in The Journal of the American Dietetic Association found the bigger the portion size on offer, the more people ate. And, although test subjects reported feeling fuller, they didn’t eat less at the next meal to compensate, leading to significantly increased energy intakes.

On the flipside, a study of 300 obese and overweight adults found those who spent the most time controlling portion size during their weight-loss and maintenance efforts were more likely to lose weight compared with those who focused on increasing physical activity, reducing fat in their diet or eating more fruit and vegetables.

Serving size deception

While portion size is how much actually ends up on your plate, the “serving sizes” on nutritional panels are recommendations determined by food manufacturers. Serving sizes can swing between unrealistically small and obesity-inducing large serves, and some products may have more serves than you’d reasonably expect in a packet.

For example, Smith’s Potato Chips Thinly Cut Sour Cream & Onion 175g packet has 3763kJ. The recommended serve size totals 581kJ – sounds OK for a snack, until you realise a serve is a laughable 27g (or about 18 chips). And there’s an unwieldy 6.5 serves per packet. In contrast, Coles Simply Less Sweet Chilli & Sour Cream Potato Snacks come in a more realistic 40g pack with 760kJ, which compares favourably with a 45g packet of Smiths Thinly Cut, which has about 981kJ.

Always consider the size of the packet, how much of it you’ll eat and the kilojoules per 100g rather than the serving size.

Small temptations

One method of having your cake and not eating too much of it is to buy your “sometimes foods” in pre-packaged portions – something diet food brands can do well.

“Along with knowing how many kilojoules are in a product, it’s been shown that smaller, controlled portions can help shave kilojoules off your daily intake,” says Funder.

As an example, a sensible portion of Cadbury Light Vanilla Ice Cream is 50g (one scoop) and has 300kJ. That said, stopping yourself at one scoop is easier said than done when there’s a tub of ice-cream on your kitchen table looking longingly up at you. This is where the controlled portions come in.

  • Cadbury Light Vanilla Ice Cream, 300kJ per 50g (one scoop) / 19c
  • Skinny Cow Vanilla Chocolate Ice Cream Stick, 340kJ per 67g / $1.00
  • Weight Watchers Creamy Vanilla Ice Cream, 25kJ per 74g pack / $1.73


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