Risk of overestimating treatment effects and generalisability of computer-based tailored dietary counselling

We read the article by Bianchi et al. with great interest and appreciate the authors’ efforts to investigate whether computer-based tailored dietary counselling has positive effects on nutrient adequacy in the diets of pregnant women⁽¹⁾. However, we have concerns about some perspectives.

Due to the nature of a single-blind, randomised controlled trial, the PANDiet score in the intervention group may have been overestimated by dietitians who were aware of the allocation of participants and also assessed their diets.

Furthermore, the inclusion of participants in a socially high-class living in an urban area may have resulted in an overestimation of the effects of the intervention. Since the intervention group appeared to have a better socio-economic status than the control group (although there were no significant differences between the arms), the authors may confirm the results obtained by comparing PANDiet scores between the arms following adjustments for socio-economic variables.

In addition, further studies are needed to confirm whether this computer-based therapy is effective for the general population (without a higher level of education or higher income and older than 35 or 40 years in rural areas) because the present study focused on participants with a relatively high level of education and higher income who were young and living in an urban area. Since 67 % of participants had an education level that was higher than a Master’s degree, 49 % had a monthly income of more than €5000 and 87 % paid attention to their diet before pregnancy, their adherence to or compliance with a series of dietetic follow-ups may have been better than that of the general population^(2,3) .

As a perspective from a dietitian, future studies are warranted to establish cost- and effort-effectiveness (i.e. whether personalised tailored therapy is worth the time and effort of dietitians).