The nutritious drink: a specialized nutrient supplement for adults and adults living with HIV in Malawi

INTRODUCTION

Undernutrition is a major problem in the world, affecting vulnerable population groups such as people living with HIV (PLHIV). Ready-to-use-therapeutic-foods or corn-soy-blends [e.g., Super Cereal (SC)] are often used to treat undernutrition among PLHIV. However, their acceptability and compliant use are not optimal. 

THESIS AIM

To develop a culturally appropriate food nutrient supplement with sensory properties tailored to the preference, primarily of PLHIV, and potentially of adults from the general population, leading to more optimal micronutrient intake.

METHODS

We conducted two qualitative studies based on Grounded Theory. In-depth interviews with a triangulation of participants and an iterative approach to data collection were used to investigate the factors influencing preferences for food and nutrient supplements among PLHIV. Based on the results of the qualitative research, we developed eight samples of a nutritious drink.

Next, we studied the olfactory and gustatory (chemosensory) function of PLHIV to assess whether they suffer from chemosensory losses that could explain possible differences in preferences for the eight samples of the nutritious drink. We used the Sniffin’ Sticks and Taste Strips to assess the olfactory and gustatory function of 100 PLHIV and 100 healthy adults for comparison.

Subsequently, 100 PLHIV and 98 healthy adults evaluated the nutritious drink samples. We used hedonic scales for assessing liking, and CATA (check-all-that-apply) questions to develop a sensory characterization of the nutritious drink samples. Penalty analysis was conducted to identify the drivers of liking and disliking of the samples for subsequent product optimization.

Our last study assessed the acceptability and ad libitum intake of the nutritious drink, RUTF, and SC. Fifty-four PLHIV evaluated the products, monadically on three consecutive days. The three food nutrient supplements were served in isocaloric portions of 1000 kcal each. Participants were instructed to consume the products ad libitum. The participants were also asked to rate their liking and wanting for each product. Time of consumption (ad libitum), the number of bites used to consume the products were also measured, and the eating rate was calculated.

RESULTS

The findings from the qualitative studies indicated that PLHIV preferred a thick beverage slightly sweet and sour as a nutrient supplement. Maheu, a maize-based drink of sweet and sour flavor and a thick, gritty consistency was utilized as a benchmark for the development of the nutritious drink samples for Malawi. The results from the study on olfactory and gustatory function, suggest that PLHIV suffer from olfactory loss. However, their gustatory function was normal.

The findings from the study using CATA questions showed clear and significant differences in the acceptability of the samples, but no significant differences in preferences between PLHIV and healthy adults. The sensory characterization of the samples made by the two groups was also similar. A preference toward sweet, somewhat sour, thick samples with a soft texture and a milky flavor was identified.

The results from the ad libitum intake study showed a significantly higher intake of the nutritious drink (356 g) compared to RUTF (107 g) and SC-porridge (312 g). The average intake of eight essential micronutrients as a percentage of target quantities was 58 % from the nutritious drink, 33 % from RUTF, and 20 % from SC. The average caloric intake from the nutritious drink, RUTF, and SC was 507, 581, and 339 kcal, respectively.

DISCUSSION AND CONCLUSIONS

The combination of qualitative research and advanced techniques from sensory science allowed us to identify a product of high acceptability and to identify directions for tailoring the sensory properties of the product to the preference of the potential consumers. A more substantial weight of food and larger quantities of micronutrients were ingested from the nutritious drink compared to RUTF and SC. The nutritious drink also had a much higher eating rate compared to the semisolid supplements. These findings suggest that nutrient-dense food supplements in liquid form may be more effective than semisolid products (e.g., RUTF and SC) in treating undernutrition among PLHIV and other adults. Future research should focus on testing the efficacy of the nutritious drink in the treatment of undernutrition in comparison to RUTF and SC.