Almost everything we think we know about food is wrong, says genetic epidemiologist and award-winning author Professor Tim Spector.
Calorie counting, the war on carbs, and the idea that there is any such thing as a super food are all myths, he tells Nine to Noon.
Best known for introducing the world to the wonders of the gut microbiome in his first book, The Diet Myth, his latest Food for Life is an eater’s guide to happy gut microbes.
Photo: supplied
Ultra-processed foods have been creeping into our diets since the 1970s, he says.
"Mainly English-speaking countries have led the way perhaps because of a lack of basic food culture. So that now in countries like UK, the US, Australia, New Zealand, around 50 percent of our energy comes from these ultra-processed foods, and probably about 70 percent of our children's.”
While such foods have fed us cheaply and have a long shelf life, they have also affected us in many negative ways, he says.
“They're changing our taste buds, they are messing up our gut microbes and they're making us overeat.”
The food industry has huge financial reach and the power to influence government policy, Spector says.
“The food industry now is so massive that it lobbies governments across the world, to make sure that no one really studies this … and sends us down these blind alleys, talking about fats and reducing saturated fat and replacing it with something else, or having a slightly lower calorie count and having a healthy sticker on the label or adding a few useless vitamins and then making sure that product is seen as healthy.”
He has no problem with ultra-processed food so much as misleading labelling. Children’s yoghurt is a glaring example, he says.
"These are billed as healthy. I've got nothing against products that are obviously unhealthy like Pepsi Cola, Coca Cola, Fanta etc; people know they’re not good for you, they're sugary and it's transparent.
"But other things like children's yoghurt which are promoted as being a healthy source of many things for children and might claim to have some added vitamins just are vehicles for sugar, artificial sweeteners, fake fruits and giving children an overly sweet tooth.
"So, they will become customers forever, of either sugar or artificial sugar.”
Breakfast cereals aimed at children are also a culprit, he says.
“They have cartoons and healthy, fun characters on the front. And it's plastered with vitamin adverts and things of how it's got all these incredible vitamins in it.
"And it's a sort of health food and combined with milk it gives everything you need for your child. And basically it's just giving your children a sugar rush with very low-quality vitamins that they wouldn’t need if they had a decent diet.”
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The public tend to believe that what they’re eating is healthy and safe, he says.
“They believe they've been tested by governments to make sure they are healthy and safe and that every time there's a new ingredient or a new artificial sweetener, a new emulsifier or glue to stick it together they've been properly tested - and of course they haven't.”
So what effects do ultra-processed foods have on our bodies?
“Most ultra-processed foods have none or very little fibre. So, the body gets a signal that it's getting food, but none of this actually reaches the gut microbes. It's all absorbed very early on.
“And so, you get sugar peaks and fat peaks, but not much fibre reaches the gut microbes which are in the lower part of our gut in the larger intestine.”
But some things do reach the gut microbes, he says.
“Several components of ultra-processed food, such as artificial sweeteners, they're all different, but there's about six on the market at the moment, and they all have slightly different actions.
"But most of them do affect the gut microbes and will cause them to produce abnormal chemicals. And this has been shown in a number of experiments these chemicals are actually pro-diabetic and act against your own healthy metabolism.”
Artificial sweeteners were long-thought to be inert, he says.
“But it turns out they are interacting with our bodies through our gut microbes. And microbes can't break them down easily, so they create a bit of a wave down there that leads to all these abnormal chemicals being produced.”
Ultra-processed foods also include emulsifiers, he says which act as glue binding parts of processed food together.
“Because ultra-processed food is made from extracts of other foods, it's not made from the whole food originally, they have to glue these powders and these liquids together to make it look like solid food again.
“When you put these into mouse models and humans you find that a proportion of people react quite badly against them and cause abnormalities in the gut microbiome.”
Food scientists have also made ultra-processed food temptingly tasty, he says.
“This is the other reason that ultra-processed foods are so damaging is that it's now being proven that if you eat an identical meal, one ultra-processed one, one whole food made at home in your own kitchen, you will probably overeat by about over 10 to 15 percent, that's about 300 calories in that day.
“Because of just the composition of the how that food is, is presented to your body.
“So, they've done such a good job, these food scientists that they can make it not only tasty, but it sort of deflects your hunger and satiety signals so that you don't feel full.”
The answer is to veer towards plants and a wide variety of them, treat your gut like a rich garden or a jungle, he says.
“Make sure that as many different species are there that can pump out all these fantastic chemicals that help your immune system.
"So, the way to do that is try and increase the number of different plants you have every week. We found the sweet spot is if you can get us to 30 plants a week, that's where your optimum gut health is.
“People might say, Oh, I can't have 30 types of kale, that's horrible. I'll never do this. But nuts and seeds are all individual plants. There's a difference between, you know, a purple carrot, and an orange one.
“People forget that herbs and spices are also plants, that some of our foods, which we've told in the past were unhealthy, but turned out to be healthy for us, like coffee is a plant and is a source of energy for your gut microbes, as well as fibre.”
