Member Matters
Which dietary recommendations for reducing free sugar intakes are most effective?
21 May 2025
Sugar is everywhere in our diets, and while it might make our foods taste great, excessive consumption of free sugar may lead to serious health problems, including obesity and chronic diseases. To help guide us in healthier eating habits, the World Health Organization (WHO) recommends that our intake of free sugars—sugars added to foods and drinks, and those found in honey, syrups, and fruit juices—should be less than 10% of our total energy intake. For even better health benefits, they suggest aiming for under 5%.
Despite these recommendations, many of us struggle to cut back on sugar. One of the reasons is that these guidelines often focus on nutrients rather than practical changes we can make in our diets. People find it hard to translate nutrient information into real lifestyle changes. To address this, WHO and the Food and Agriculture Organization (FAO) have begun advocating for food-based guidelines that focus on overall dietary patterns instead of isolating individual nutrients.
Making sense of sugar reduction
Researchers have been exploring effective strategies to help people reduce their free sugar intake. One successful approach involves behavioral interventions. For example, encouraging individuals to swap sugar-sweetened drinks with low-kilojoule or unsweetened alternatives has shown significant reductions in sugar consumption. These findings highlight the importance of practical, food-based strategies that can make it easier for us to heed sugar reduction guidance.
A recent randomised control trial study (1) conducted in the UK demonstrated the effectiveness of various dietary recommendations aimed at adults consuming too much free sugar. The study involved 242 participants who were divided into four groups for a 12-week period:
1. **Nutrient-based advice (N)**: This group learned to reduce their free sugar intake to below 5% of their total energy intake (TEI), including tips on how to identify added sugars in foods.
2. **Nutrient- and food-based advice (NF)**: This group received the same advice as the nutrient group, plus additional recommendations on which common foods are high in sugar.
3. **Nutrient-, food-, and substitution-based advice (NFS)**: This group got all the information from the first two groups, plus guidance on replacing high-sugar foods with low-sugar alternatives, including the use of low-calorie sweeteners.
4. **Control Group**: Participants in this group did not receive any specific advice about sugar intake and were asked to keep diet diaries.
Key findings from the study
At the end of the intervention, all the groups receiving advice saw significant reductions in their free sugar intake compared to those in the control group, who did not change their eating habits as dramatically. Notably, the NFS group achieved the largest reduction, cutting their free sugar intake by a significant 3.3% of TEI. The NF group followed closely with a reduction of 2.9%, while the N group reduced their intake by 2.5%. In comparison, the control group managed only a 1.2% reduction.
Moreover, the participants in the NFS group not only consumed less sugar but also improved their overall diet. They decreased their intake of sugar-rich foods while increasing their consumption of low-kilojoule sweetened options. Interestingly, participants in the intervention groups also experienced modest weight loss over the 12 weeks, ranging from 0.7 to 1.4 kg, compared to just 0.2 kg for the control group.
It’s important to note, however, that while participants in the intervention groups reduced free sugar intake, their overall diet composition—including total energy intake and macronutrient distribution—remained largely unchanged. The most significant weight changes were observed in the NF and NFS groups. However, these weight changes were not strongly correlated with the reductions in free sugar intake, indicating that other factors may have contributed to the observed weight loss.
Enhancing adherence to dietary recommendations
The study highlighted an important point regarding adherence to dietary recommendations. Adherence was measured as consuming less than 2% of TEI from free sugar or achieving an intake of 5% or less. The highest adherence rates were seen in the NF group. This indicates that when people receive a combination of nutrient and food-based information, they are more likely to comply with dietary guidelines.
Caution
The main findings of the study relied on diet diaries, which can sometimes be inaccurately filled out, although they usually are valid for tracking what people eat. The calculation of free sugar content was based on the available information and might not accurately reflect all the different products consumed, which could affect the results. Also, the study mostly included women, so the results may not apply as well to men or the entire population. Lastly, the participants chose themselves and were motivated to change their diets as the study was advertised as a study of dietary change, to recruit those who might be inclined to comply with dietary change requests. This means the effects seen might be stronger than what would be expected in the general public.
Nevertheless, the outcomes of this study emphasise that dietary recommendations that include practical food guidance—especially those focusing on substitutions—are particularly effective in helping us lower our sugar intake and improve our diets.
Reference
- Boxall LR, Arden-Close E, James J, Appleton KM. Effects of dietary recommendations for reducing free sugar intakes, on free sugar intakes, dietary profiles and anthropometry: a randomised controlled trial. British Journal of Nutrition. 2025;133(5):694-710. doi:10.1017/S0007114525000339
