Paleo diets cut out dairy; low-carb aficionados banish starchy foods. Gluten-free has become a foodie's trend while vegetarians and vegans shun meat.
“That means that all you’re left with is a kale smoothie and some vitamin pills. We’re moving towards exclusion diets that are less diverse than before and that’s bad,” said Tim Spector, Professor of Genetic Epidemiology and director of the British Gut Microbiome Project.
It's bad for our microbiome and gut bacteria, which thrive on food diversity, and need a variety of fresh fruit and vegetables, fibre, cheese, polyphenols and antioxidants. Spector believes it is this lack of diversity that is fuelling rates of obesity and type 2 diabetes.
Add to this the lack of ingredient diversity in processed foods, and our microbiome is literally starving. In the Western world, we may have the illusion of food choice with literally thousands of products to choose from on supermarket shelves, but the reality if we have never eaten so few ingredients.
Some studies have also shown that emulsifiers, preservatives and artificial sweeteners to have a negative effect on gut bacteria, Spector told Food Vision delegates in London last week.
“This is important for the food industry to understand; they [these ingredients] have been tested for causing cancer in rats and have been approved but the effect on gut hasn’t. It’s a warning against the over artificial trend in food.”
Although faecal transplants (imaginatively nicknamed ‘crapsules’ in the US) may not make for appetising dinner table talk, Spector believes this gut health is an important conversation the food industry should be engaging in.
He predicts an increased interest in gut health and how food impacts it. He is currently involved in opening a new gut health food bar in London (“based on science not publicity”) where people eat foods based on the diet of the Hadza hunter and gatherer tribe in Tanzania.
This tribe has one of the most diverse diets – and hence one of the most diverse microbiomes – in the world.