A new six-month trial suggests that changing how much sweet-tasting food people eat does not alter how much they enjoy sweetness. Researchers also found no meaningful differences in several measures related to heart disease and diabetes risk among people who ate diets with high, low, or average levels of sweetness.
The findings raise questions about public health advice that encourages people to reduce sweet-tasting foods as a way to combat overweight and obesity. The researchers argue that the more important targets may be sugar intake and energy-dense foods rather than sweetness itself.
Sweetness Intake Did Not Change Taste Preferences
The study was conducted by researchers at Wageningen University and Research in the Netherlands and Bournemouth University in the UK. The findings were published in the American Journal of Clinical Nutrition.
“People have a natural love of sweet taste which has led many organizations, including the World Health Organization, to offer dietary advice on reducing the amount of sweetness in our diets altogether,” said Katherine Appleton, Professor in Psychology at Bournemouth University and corresponding author for the study. “However, our results do not support this advice, which does not consider whether the sweet taste comes from sugar, low-calorie sweeteners, or natural sources,” she added.
Researchers recruited 180 participants and divided them into three groups. One group ate a diet containing a high amount of sweet-tasting food, another ate a diet with a low amount, and the third followed a diet with an average level of sweetness.
The sweet taste in the foods came from several sources, including sugar, naturally occurring sweetness, and low-calorie sweeteners. This distinction matters because foods can taste sweet for very different nutritional reasons. Fruit, for example, contains naturally occurring sugars along with vitamins, fiber, and other nutrients, while some processed foods may contain added sugar without offering the same nutritional benefits.
Six Months of Testing Found Little Difference
After one month, three months, and six months, participants were asked whether their liking for sweet foods or their perception of sweetness had changed.
Researchers also tracked body weight and collected blood and urine samples. These samples were used to look for changes in markers associated with diabetes risk and cardiovascular health. Such markers can help researchers assess whether a dietary change is affecting processes linked to blood sugar control, metabolism, or heart health.
At the end of the six-month trial, the researchers found no significant differences among the three groups in any of the measures they examined. People who ate more sweet-tasting foods did not appear to develop a stronger preference for sweetness, while those who ate fewer sweet foods did not appear to lose their taste for it.
Participants also tended to return on their own to their previous levels of sweet food consumption after the study ended.
Researchers Question Advice to Reduce Sweet Foods
Based on the results, the research team says public health organizations may need to reconsider recommendations that broadly target sweet-tasting foods as part of efforts to address overweight and obesity.
The researchers emphasize that sweetness and sugar are not the same thing. A food can taste sweet because it contains sugar, a low-calorie sweetener, or naturally occurring sugars. At the same time, some foods that do not taste especially sweet can still contain substantial amounts of sugar.
“It’s not about eating less sweet food to reduce obesity levels,” Professor Appleton said. “The health concerns relate to sugar consumption. Some fast-food items may not taste sweet but can contain high levels of sugar. Similarly, many naturally sweet products such as fresh fruit and dairy products can have health benefits. Public advice therefore needs to concentrate on how people can reduce the amount of sugar and energy-dense foods they consume,” she concluded.
Energy-dense foods contain a relatively large number of calories in a small amount of food. Many highly processed foods fall into this category because they can be rich in added sugars, fats, or both.
The study suggests that simply reducing exposure to sweet tastes may not be enough to change people’s preferences or improve the health measures examined over six months. Instead, the researchers say dietary guidance may be more useful when it focuses on the nutritional quality of foods, particularly their sugar and calorie content, rather than whether they taste sweet.