Science
Should we keep children away from sugar for their first 1000 days?
Key Points
When I had my first child, I tried to minimise his sugar consumption. I made him a zucchini puree for his first meal (not a major hit) and politely declined on his behalf when anyone offered him sweets. By the time I had my second and third children, however, I had largely given up.
When I had my first child, I tried to minimise his sugar consumption. I made him a zucchini puree for his first meal (not a major hit) and politely declined on his behalf when anyone offered him sweets. By the time I had my second and third children, however, I had largely given up. I realised that trying to shield them from sugar was like trying to run through rain without getting wet, and I suspected I needed to chill out anyway.
My interest was thus piqued by a recent study that used a neat natural experiment to investigate the long-term health effects of sugar exposure during our first 1000 days. This was defined as the period from conception to age 2, a time that is increasingly understood to be a critical window in which dietary exposures have lasting repercussions.
Jiazhen Zheng at the Hong Kong University of Science and Technology and his colleagues analysed the health of people whose first 1000 days coincided with post-war sugar rationing in the UK in the early 1950s and compared it with those who were conceived just after that period.
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During the rationing period, each person in the UK was only allowed around 40 grams of sugar per day, except for children under the age of 2, who were allocated none. Presumably these infants would have shared some of their families’ rations, but their sugar intake would still have been low compared with today, when a child can consume 40 grams of sugar in just two glasses of juice.
When sugar rationing ended in the UK in 1953, sugar was enthusiastically embraced again and average consumption doubled to 80 grams per day within a year.
The researchers used data from the UK Biobank to compare 40,000 adults who spent some or all of their first 1000 days under sugar rationing with 23,000 whose first 1000 days came just afterwards, during the post-rationing sugar boom.
Astonishingly, the amount of sugar they were exposed to as babies 70 years ago seems to still be influencing their health today. The rationed individuals are more likely to still be alive, and markers of ageing in their cells suggest they are biologically “younger” than those who were never rationed. They also have lower organ ages, particularly for their hearts, lungs and livers.
This probably explains why they have been less likely to develop cancer, heart disease, type 2 diabetes, stroke, rheumatoid arthritis, cataracts, dementia, liver failure, chronic kidney disease, chronic obstructive pulmonary disease and many other conditions. The longer they spent under rationing during their first 1000 days, the more protected they seem to be now.
The long-lasting impact of early sugar
How could this be? Zheng and his colleagues believe that sugar exposure in utero and during infancy shapes ageing processes in our cells, which are then programmed for life. Early exposure to sweet foods may also establish permanent preferences for them, because the study found that people born under rationing still eat less sugar today than those who escaped it. I can relate to this because, as a child, I had a bowl of ice cream after dinner every night, and it has taken me years as an adult to break this habit.
I don’t think we need to implement a full sugar ban for children in their first 1000 days, since this would be impractical and downright mean. However, as the adults who supply their foods, I do think we have a responsibility to lower their sugar consumption to healthier levels.
For one, we should limit the amount of sugar in commercial baby and toddler foods. According to European guidelines, children under the age of 2 should consume less than 15 grams a day of free sugar, which is added table sugar plus sugars from fruit juice, syrups and honey. But when I examine the labels on yogurt pouches, snack bars, “puffs” and “melts”, rice cakes, and fruit and vegetable purees in the baby aisle at my local supermarket in Australia, I find that many contain close to 15 grams of free sugar in a single serving. It’s easy to mistake these products for health foods because they are adorned with images of fruit and vegetables alongside virtuous-sounding labels like “organic”, “high-protein” and “prebiotic”.
In August 2025, the UK introduced voluntary industry guidelines appealing to baby food manufacturers to cut the amount of sugar in their products by the end of February 2027. However, 1 in 5 of these products still contains excessive sugar, and no such guidelines have yet been introduced in Australia and the US.
As children get older, I also believe we need to disentangle sugar from sport and other activities. In every sport that my children have played, they have received a bag of sweets at the end of the season as a reward for participating. Maybe they could get a ribbon or certificate instead, or simply revel in the enjoyment of being active with friends? Similarly, they are given sweets for reading a certain number of books at school, when they go to the hairdresser and when they get their flu shot. It all adds up, and I don’t believe it’s necessary, since I think children are more intrinsically motivated and resilient than we give them credit for.
Sugar has also been on my mind because I’ve been writing an article about the growing use of GLP-1 weight-loss drugs for treating severe obesity in children under the age of 12. It’s hard for children to resist when they are constantly bombarded with sweet temptations, which are fuelling the obesity crisis. Surely removing some of these temptations is preferable to medicating children, possibly for life.
I was mulling all of this recently while organising my daughter’s sixth birthday party. On one hand, I didn’t want to overload her guests with sugar, but I also didn’t want to be an uptight parent denying them simple joys. In the end, we settled somewhere in-between: we had a sweet cake with highly artificial blue icing, but no bowls of sweets or party bags. The kids didn’t seem to mind, and some parents quietly thanked me for saving them from an afternoon of sugar highs and lows. Our children won’t remember what they ate in their first 1000 days, but their 70-year-old bodies might.