New research finds your sweet tooth might be genetic

If you're the person who always reaches for dessert while everyone else is happy to skip it, your sweet tooth may not be entirely down to willpower.

New research suggests that our genes could play a role in how much we enjoy sweet foods, and even how much of them we eat.

We all know someone who can inexplicably just open a chocolate bar, eat one single square and then leave the rest in the cupboard as they don't fancy another bit.

If that baffles you, and you simply must polish off the lot, it might just be your genes instead.

Preliminary research presented at the American Society for Nutrition’s annual meeting has found a link between genetic differences and people's preferences for sweet, salty and fatty foods.

Researchers from the Center for Genomic Medicine at Massachusetts General Hospital analysed data from nearly 500,000 people in the UK Biobank, one of the world's largest biomedical databases.

Whether you think this looks yuck or yum could come down to your genetics (Getty Stock/Peter Dazeley)

Could your sweet tooth be in your DNA?

The researchers looked at participants' genetic information alongside questionnaires covering food preferences, diet and health.

They then developed genetic scores designed to measure a person's inherited tendency to prefer different tastes.

The results suggested that people with a stronger genetic predisposition towards sweet tastes consumed around 7g more sweet food per day, on average, than those with a lower genetic predisposition.

Seven grammes might not sound significant, but researchers say small differences can accumulate when they become a daily habit.

The study also found that genetic preferences for sweet and fatty foods were associated with higher body weight and a modestly increased risk of type two diabetes.

Importantly, however, the research does not mean that genes determine whether someone will develop obesity or type 2 diabetes.

The findings are still preliminary and have not yet been peer-reviewed or published in a scientific journal, so they should be interpreted with caution.

Some people even perceive sugar to be more sweet than others (Getty Stock/Simple Images)

Why do some people crave sugar more than others?

Scientists have long known that people experience sweetness differently.

Our taste buds contain receptors that detect sweet compounds, with two proteins, TAS1R2 and TAS1R3, playing a key role in sweet taste perception.

Genetic differences can affect how these receptors function, potentially influencing how strongly someone experiences sweetness.

But the story is more complicated than having a single 'sweet tooth gene'.

Previous research has found that several genetic factors may influence sweet taste perception, food preferences and sugar intake.

A genome-wide association study involving UK Biobank participants also found genetic associations involving sugar consumption and suggested that genes affecting the brain may be involved in both sweet taste perception and sugar intake.

This means your desire for chocolate, biscuits or a sugary drink could be influenced by a combination of biological factors rather than one particular gene.

Research has found our DNA can have a lot to do with it (Getty Stock/Peter Dazeley)

Your environment still matters

While genetics may influence how appealing sweet foods are, they are only part of the picture.

What we eat is also shaped by our upbringing, culture, habits, food availability, sleep, physical activity and the foods we regularly consume.

Previous research has found that sweet taste preferences are influenced by both genetic and environmental factors, meaning our preferences are not necessarily fixed for life.

This is an important distinction because having a genetic tendency towards sweet foods does not mean you are destined to eat excessive amounts of sugar.

Instead, the findings could eventually contribute to more personalised approaches to nutrition, where dietary advice takes individual differences in taste preferences into account.

Should you cut out sugar?

Not necessarily. The research is about a tendency to prefer sweet foods, rather than suggesting that all sugar-containing foods are unhealthy.

Naturally occurring sugars in foods such as fruit and milk come alongside other nutrients, while added sugars are commonly found in sweets, biscuits, cakes, sugary drinks and many processed foods.

If you regularly crave sweet foods, simple changes can help.

Choosing fruit when you want something sweet, reducing the amount of added sugar in drinks and gradually adjusting your taste preferences can all be practical steps.

Ultimately, your genes may help explain why you have a sweet tooth, but they do not have the final say over what ends up on your plate.