Children scarfing down lip-smacking goodies instead of their fruits and vegetables may be setting themselves up for a lifetime of battling the bulge or even Type 2 diabetes, new research suggests.
Researchers at the University of Calgary used rats in experiments to show that diet in childhood and adolescence can permanently alter how genes react and cause changes in hormones that make you feel full.
This suggests that what you eat as a child can have a huge impact on health later in life, said author Raylene Reimer.
The researchers fed baby rats three different diets from a very young age: one with high protein, one with high fibre and one balanced.
When the rats reached adulthood they were fed a high-fat, high-sugar diet mirroring typical North American eating habits — including sugar, lard and soybean oil.
All the rats were allowed to indulge in as much junk food as they wanted. It turned out that those reared on the high-protein diet wanted a lot more — and gained much more weight and body fat — than those rats that were fed the high-fibre diet as youngsters. Those rats eating the normal, balanced diet — which Reimer said would be like following Canada’s Food Guide — stayed almost as slim as the fibre group.
“What we saw was very striking in terms of their body weights,” said Reimer. “We saw that the high-fibre diet was actually protective against obesity, whereas the high-protein diet was very much promoting obesity later on in life.”
Reimer says it comes down to how the genes we are born with are expressed. We can’t change our genetic makeup, but we can influence how our genes will react. For example, someone who is fed well in childhood will probably grow taller than someone who’s malnourished — even if both start out with the same genetic base.
In the study, the high-fibre diet caused an increase in the activity of a gene that controls the release of hormones that make you feel full.
“The diets actually affect your gene expression that then causes your body to react different. It changes the biology of your body.”
The results could explain why some people find it impossible to shed extra pounds despite dieting and exercise, while others never seem to gain an ounce, said Reimer.
A 2007 Statistics Canada survey found 16 per cent of adult Canadians were obese based on their reported weights and heights, and 32 per cent were overweight.
“This might be an explanation, first, of the rapid rise in obesity rates that’s occurred, and also why some individuals find it very much more difficult to control body weight and prevent weight gain.”
Reimer said the message from her study is that everyone, including children and pregnant women, needs to eat a balanced diet full of whole grains, fruits and vegetables.
Most people only get about half the fibre they need in a day, something research has shown again and again can lead to problems, she said.
“That can have implications for body weight (and) for Type 2 diabetes. Cancer, as well, has been linked to dietary fibre intake.”
