Sensory Influences on Salt, Sugar and Fat Intake

Role of food choice motives in the socio-economic disparities in diet diversity and obesity outcomes in Kenya

BACKGROUND

The increased prevalence of overweight and obesity, along with high diet diversity, is observed among higher socio-economic groups in Sub-Saharan Africa. One contributing factor to these observed variations is food choice motives. However, the role of these motives in explaining the observed differences has not been thoroughly explored in this context.

OBJECTIVE

This study investigates whether there are significant differences in food choice motives among socio-economic groups and whether these variations can partly explain the socio-economic disparities in diet diversity and overweight and obesity outcomes.

METHODS

This study utilizes cross-sectional data from four counties in Kenya: Kiambu, Murang'a, Uasin Gishu, and Nakuru. The survey employed a three-stage cluster sample design to gather data using structured questionnaires on food choice motives, diet diversity, and anthropometrics from 381 adults in 2022. The mediating effects of 8 food choice motives (health, mood, convenience, sensory appeal, natural content, price, weight control, and familiarity) were analyzed using the Karlson-Holm-Breen method.

RESULTS

The results show that individuals with higher household incomes place greater importance on health, mood, sensory, and weight concerns. The probability of an overweight and obesity outcome increases by 19% for a standard deviation change in the asset score, and by 8% for a standard deviation change in the years of schooling. Sensory motives significantly mediated these relationships. Sensory motives explained 29% of the income-BMI association and 30% of the education-BMI relationship. Higher education was also associated with increased diet diversity (β = 0.36, P < 0.001) mediated by higher health and sensory concerns.

CONCLUSIONS

The findings suggest significant differences in food choice motives among socio-economic groups, which contribute to outcomes such as overweight and obesity. Therefore, educational and other policies aimed at reducing obesity should also address food choice motives, while considering the disparities among socio-economic segments within populations.

Salt content impacts food preferences and intake among children

Decreasing dietary sodium intake, which can be achieved by reducing salt content in food, is recommended. Salt contributes to the taste of foods and makes them more enjoyable. Whether a food is liked or disliked is an important determinant of food intake, especially among children. However, the role of salt in children's food acceptance has received little attention. The impact of salt content on children's hedonic rating and intake of two foods was investigated in children. Using a within-subject crossover design, we recruited 75 children (8–11 years) to participate in five lunches in their school cafeteria. The target foods were green beans and pasta. The added salt content was 0, 0.6 or 1.2 g/100 g. The children's intake (g) of all lunch items was measured. The children provided their hedonic rating of the food, a preference ranking and a saltiness ranking in the laboratory. Children could rank the foods according to salt content, and they preferred the two saltier options. A food-specific effect of salt content on intake was observed. Compared to the intermediate level (0.6 g salt/100 g), not adding salt decreased green bean intake (−21%; p = 0.002), and increasing the salt content increased pasta intake (+24%; p<0.0001). Structural Equation Modeling was used to model the relative weights of the determinants of intake. It showed that the primary driver of food intake was the child's hunger; the second most important factor was the child's hedonic rating of the food, regardless of its salt content, and the last factor was the child's preference for the particular salt content of the food. In conclusion, salt content has a positive and food-specific effect on intake; it impacted food preferences and intake differently in children. Taking into account children's preferences for salt instead of their intake may lead to excessive added salt.

Expected satiation after repeated consumption of low- or high-energy-dense soup

We investigated whether repeated consumption of a low-energy-dense (LED; 208 kJ/100 g) or high-energy-dense (HED; 645 kJ/100 g) soup modifies expectations relating to the satiating capacity of the food, and its subsequent intake. In study 1, participants consumed either a novel-flavoured LED (n 32; 21 (SD 1·6) years, BMI 21·4 (SD 1·6) kg/m(2)) or HED soup (n 32; 21 (SD 1·6) years, BMI 21·3 (SD 1·7) kg/m(2)). Soup was served in a fixed amount on days 1-4 and ad libitum on day 5. 'Expected satiation' was measured on days 1, 2 and 5. Expected satiation did not change after repeated consumption of the LED or HED soup. Ad libitum intake did not differ between the LED (461 (SD 213) g) and HED soup (391 (SD 164) g). Only on day 1, expected satiation was higher for the HED soup than for the LED soup (P = 0·03), suggesting a role for sensory attributes in expected satiation. In study 2, thirty participants (21 (SD 1·6) years, BMI 21·3 (SD 1·7) kg/m(2)) performed a single measurement of expected satiation of the LED and HED soup, and four commercially available types of soup. Ratings on sensory attributes were associated with expected satiation. Results on expected satiation coincided with those of study 1. Thickness and intensity of taste were independently associated with expected satiation. Expectations may initially rely on sensory attributes and previous experiences, and are not easily changed.

Explaining variability in sodium intake through oral sensory phenotype, salt sensation and liking

Our sodium-rich food supply compels investigation of how variation in salt sensation influences liking and intake of high-sodium foods. While supertasters (those with heightened propylthiouracil (PROP) bitterness or taste papillae number) report greater saltiness from concentrated salt solutions, the non-taster/supertaster effect on sodium intake is unclear. We assessed taster effects on salt sensation, liking and intake among 87 healthy adults (45 men). PROP bitterness showed stronger associations with perceived saltiness in foods than did papillae number. Supertasters reported: greater saltiness in chips/pretzels and broth at levels comparable to regular-sodium products; greater sensory and/or liking changes to growing sodium concentration in cheeses (where sodium ions mask bitterness) and broths; and less frequently salting foods. PROP effects were attenuated in women. Compared with men, women reported more saltiness from high-sodium foods and greater liking for broth at salt levels comparable to regular-sodium products. Across men and women, Structural Equation Models showed PROP and papillae number independently explained variability in consuming high-sodium foods by impacting salt sensation and/or liking. PROP supertasters reported greater changes in sensation when more salt was added to broth, which then associated with greater changes in broth liking, and finally with more frequent high-sodium food intake. Greater papillae number was associated with less frequent high-sodium food intake via reduced liking for high-fat/high-sodium foods. In summary, variation in sensations from salt was associated with differences in hedonic responses to high-sodium foods and thus sodium intake. Despite adding less salt, PROP supertasters consumed more sodium through food, as salt was more important to preference, both for its salty taste and masking of bitterness.

Sequential responses to high-fat and high-calorie feeding in an obese mouse model

OBJECTIVE

Reports on the immediate and long-term responses to high-fat and high-calorie (HFC) feeding are controversial. Therefore, we examined the sequential effects of an HFC diet.

METHODS AND PROCEDURES

C57BL/6J mice were randomly assigned to consume either the control (C) or the HFC diet. Body weights and food intake were measured weekly and other measurements at weeks 2, 4, and 10. Microarrays were used for screening the transcriptional response of the livers at the three time points. Genes, encoding enzymes regulating key steps of lipid metabolism, were then selected from the microarray data for validation by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) and their protein expression by western blot assays.

RESULTS

Mice fed with HFC diet for 2 weeks showed no increase in food intake and no difference in weight gain compared to the C mice. At weeks 4 and 10, the HFC mice increased their food intake and gained more weight than their controls (by 1.4 times and 2.5 times, respectively) (P<0.01 at week 10). Genes involved in fatty acid oxidation (FAO) were initially upregulated and then downregulated, whereas the lipogenic genes and genes involved in cholesterol synthesis showed reverse trends. The differential mRNA expression of Cpt1L, Fas, and Hmgcr were confirmed by RT-PCR and their protein expression by western blot assays.

DISCUSSION

Our findings suggested that when mice were fed an HFC diet, they could develop initial compensatory response to resist the increased energy balance; however, a prolonged consumption of an HFC diet appeared to disrupt this adaptation.

Short- and long-term effects of changes in pleasantness on food intake

This study concerns the effects of pleasantness on ad libitum food intake, liking and appetite over 5 successive days. Pleasantness was manipulated by varying the salt level in bread. Thirty-five students consumed ad libitum sandwiches for lunch, made with bread individually perceived as low, medium or high in pleasantness, in a balanced cross-over design. Pleasantness and desire-to-eat the sandwich were rated at first bite, after the consumption of each sandwich and at the end of the lunch. Fullness was rated just before and at several intervals after lunch. On the first day, the students ate less of the least pleasant bread than of the medium and most pleasant bread. On the fifth day, however, consumption of all breads was similar. For the least pleasant bread, energy intake at lunch, desire-to-eat and fullness, all increased over days, whereas these variables remained constant for the medium and most pleasant bread. Mean pleasantness ratings for all breads remained unaltered across the days. We conclude that, with repeated exposure, the desire-to-eat, fullness and intake of a less preferred food can increase over time. Thus, the relationship between pleasantness and food intake changes over this period.

Geriatric oral health and its impact on eating

OBJECTIVE

Adequate food and fluid intake and nutritional health are requisites for sustaining life. The oral-pharyngeal region has evolved multiple, highly regulated processes to ensure that the intake, chewing, and swallowing of foods and beverages is maintained. The objective of this paper is to identify the independent and collective roles of oral health on eating in older people.

DESIGN

Research reports from peer-reviewed scientific journals. Hypothesis-driven research that objectively examined taste, smell, dental and oral mucosal health, dental prostheses, chewing, and swallowing in the context of aging.

DATA EXTRACTION AND SYNTHESIS

Data results were extracted independently by multiple observers. A qualitative synthesis of data results from independent studies was made in order to form conclusions regarding the role of oral health on eating in older people.

CONCLUSIONS

Many oral functions remain intact in healthy older adults. However, significant alterations arise from oral and systemic diseases and their treatments, and these may have a profound effect on eating, drinking, and the nutritional status of older individuals. The care of older persons with smell, taste, dental/alveolar, oral mucosal, chewing, and swallowing problems requires a multidisciplinary team of health care providers. Recognition of the interrelationship between oral, pharyngeal, and systemic physiological processes will help practitioners identify the etiology of these disorders and implement appropriate therapy.