New WHO Draft Guidelines and Research on Carbohydrate Quality

Findings from two recent scientific reports suggest that the quality of carbohydrates can impact overall diet quality. While the search for the best marker for carbohydrate quality continues, new research considers a number of quality factors such as how quickly carbohydrates are metabolized and release glucose into the body, the proportion of sugars, and amount of dietary fibre and other nutrients, as important in developing dietary guidelines for carbohydrate intake.  Below are highlights from a new WHO proposed draft guideline on carbohydrate intake as well as an expert review evaluating a new carbohydrate scoring system that may help in developing guidelines for improving dietary patterns.  

1. On October 7, 2022, the World Health Organization proposed a “Draft Guideline on Carbohydrate Intake”, based on assessing available evidence from systematic reviews using the GRADE approach. The draft guideline primarily focuses on carbohydrate quality and provides guidance on dietary fibre and “food sources of carbohydrate with proven health benefits in terms of important health outcomes”.  The scope of this guideline does not include an update to the previous WHO guidance on amount of total carbohydrate intake which suggests that a range of total carbohydrate intake (40 – 70% of total energy) appears to be compatible with a healthy diet.

   Draft recommendations that were open for public consultation until November 7, 2022, include:

   •    Carbohydrate intake should come primarily from whole grains, vegetables, fruits, and pulses. 

   •    An intake of at least 400 g of vegetables and fruits per day for adults, and at least 25 g/day of naturally occurring dietary fibre as consumed in foods.

   •    Varying amounts of fruits and vegetables (250-400 g/day) and dietary fibre (15-25 g/day) were recommended for children and adolescents of different age groups.

   The WHO will use the results of the consultation to finalize the guideline by addressing any overall clarity considerations, implications for adaptation and implementation of the guideline, any context and setting‐specific issues and any errors of fact or missing data.

   

2. A recent review suggests that in addition to fibre and sugars content, other factors such as sodium, potassium, and whole grain content, should be included in carbohydrate food quality metrics to better reflect current dietary guidance.  The report introduces and tests a new carbohydrate food scoring system – the Carbohydrate Food Quality Score (CFQS) – and demonstrates that the proposed expanded metrics of carbohydrate quality align with the US 2020-2025 dietary recommendations.

For more information: 

• World Health Organization. Launch of the public consultation o/n the WHO draft guideline on carbohydrate intake. 2022. 
• Drewnowski, A.; Maillot, M.; Papanikolaou, Y.; Jones, J.M.; Rodriguez, J.; Slavin, J.; Angadi, S.S.;  Comerford, K.B. A New Carbohydrate Food Quality Scoring System to Reflect Dietary Guidelines: An Expert Panel Report. Nutrients 2022, 14, 1485. https://doi.org/10.3390/nu14071485