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Some food outlets have been supersizing portion sizes and it would be good to go back to smaller amounts, a New Zealand health professor says.
In an article in the medical journal The Lancet, adviser to the UK government on obesity, Professor Naveed Sattar, said ready to eat portion sizes were calibrated towards an adult male, and smaller options should be available for women, children, and shorter people.
The article recommended "food outlets offer at least two portion sizes for single-portion, ready-to-eat products, differing by around 25 percent - the average difference in energy requirements between men and women and priced fairly". It said this would also help provide more appropriate portion sizes for children and shorter people.
Auckland University professor of global health and nutrition Boyd Swinburn told Morning Report the basic physiology of that made sense in the sense that smaller people needed smaller portion sizes.
Experts believe meal portions behind rise in obesity rates
"Whether it's going to go all the way to having multiple portion sizes available I'm not sure, but we have been at risk of Americanisation and supersizing and we've seen that with a number of areas and takeaways and the upsizing and muffins are a big one as well," he said.
"I think it would be good if we could get back to smaller portion sizes."
Swinburn said ultra processed foods were the main driver for obesity.
"The body does work pretty well in managing to have energy intake according to its needs but it can get fooled and the place where it really gets fooled is with ultra processed foods which are highly palatable and very dense in energy. So we think we're just eating enough for our body ... but because it's so energy dense, so full of calories, we end up overeating," he said.
"It's mainly an issue related to the ultra processed foods rather than real foods that the serving sizes apply to."
Swinburn said as part of his research he had recently been developing a mathematical model for energy balance.
"It is interesting how much the lean body mass dictates what we eat and how much we eat. It's really this intersection between this physiology we have and the ultra processed food environment that is driving our obesity epidemic.
"The way the energy dense food sort of fools our system if you like and we end up passively overeating it and slowly gain weight over time."
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