Have a sweet tooth? Blame your genes

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Ever find yourself fantasising about decadent sweets on the last few miles of your run? Some of us can’t wait (me included!) to get our hands on an ice cream sundae!

But some of my runner friends find their teeth aching at the mere thought of an indulgence as sweet as that. Countless people also avoid treats believing that eating them causes your body to crave more sugary foods. However, a recent study proposes that your genes might be responsible for your perception of sweet.

The researchers selected a sample of 1,901 adolescents and young adults between the ages of 12 and 26. The sample included 243 pairs of identical twins, 452 pairs of fraternal twins and 511 unpaired individuals. The researchers asked the participants to taste and rate the sweetness intensity of four sweeteners: glucose, fructose, aspartame and neohesperidine dihydrochalcone (NHDC). Glucose and fructose are natural sugars that supply calories, while aspartame and NHDC are synthetic, non-caloric sweeteners.

The study found a common genetic factor appeared to be responsible for more than 75 per cent of the genetic variance in the four sweeteners. This suggests the differences in perceived sweet intensity are due to a single set of genes. The variation in sweet perception may lead those born with a weak sweet perception to sprinkle more sugar on their strawberries to achieve the same level of sweetness as others.

The researchers also discovered a shared environment had little influence on sweet perception. Assuming the twin pairs ate similar foods during childhood, this result questions the belief that eating foods with high sugar content makes people insensitive to sweetness and causes them to eat more sugar.

Although it seems sweetness perception may be due to genetics, it’s still important to consume less than 10 per cent of total daily calories from added sugars. The FDA is currently considering setting a Daily Value for added sugars and noting amounts on food labels.

Got a sweet tooth? These options will satisfy your craving while offering a nutritional boost:

Fresh and dried fruit
Both options are rich in vitamins, minerals, and fiber. When choosing dried fruit, stick with unsweetened and watch the serving size (no more than 40g) since the calories can add up fast.

Fruit iced lollies
Make your own with fresh or frozen fruit and 100 per cent fruit juice. Pour into a mould, freeze and enjoy. You can also buy fruit-based lollies, but read the ingredient list to make sure they contain mostly real fruit and not added sugars.

Dark chocolate covered almonds
A 40g serving will satisfy your sweet tooth while providing a dose of healthy fats and runner-friendly antioxidants.