Sweet/Fat Preference Taste in Subjects Who are Lean, Obese and Very Obese

Is obesity associated with taste alterations? a systematic review

Background

Obesity is a growing chronic public health problem. The causes of obesity are varied, but food consumption decisions play an important role, especially decisions about what foods to eat and how much to consume. Food consumption decisions are driven, in part, by individual taste perceptions, a fact that can influence eating behavior and, therefore, body mass.

Methodology

The searches were conducted in the electronic databases PubMed, Web of Science, Scopus, Lilacs, and the grey literature (Google Scholar and Open Grey). The acronym PECO will be used, covering studies with adult humans (P) who have obesity (E) compared to adult humans without obesity (C), having as an outcome the presence of taste alterations (O). After searching, duplicates were removed. The articles were first evaluated by title and abstract, following the inclusion and exclusion criteria; then, the papers were read in full. After the studies were selected, two reviewers extracted the data and assessed the individual risk of bias and control statements for possible confounders and bias consideration. The narrative GRADE system performed the methodological quality assessment using the New Castle Ottawa qualifier and analysis of certainty of evidence.

Results

A total of 3782 records were identified from the database search, of these 19 were considered eligible. Forty percent of the eligible studies show that there was an association between obesity and different taste alterations for different flavors comparing with normal weights adults. In the methodological quality analysis of the nineteen studies, which assesses the risk of bias in the results, fifteen showed good methodological reliability, three showed fair methodological reliability, and one showed low methodological reliability.

Conclusion

Despite methodological limitations, the results of the studies suggest the existence of a association between obesity and taste alterations, but further investigations with more sensitive methodologies are necessary to confirm this hypothesis.

Systematic review registration

https://osf.io/9vg4h/, identifier 9vg4h.

Taste of Fat and Obesity: Different Hypotheses and Our Point of View

Obesity results from a temporary or prolonged positive energy balance due to an alteration in the homeostatic feedback of energy balance. Food, with its discriminative and hedonic qualities, is a key element of reward-based energy intake. An alteration in the brain reward system for highly palatable energy-rich foods, comprised of fat and carbohydrates, could be one of the main factors involved in the development of obesity by increasing the attractiveness and consumption of fat-rich foods. This would induce, in turn, a decrease in the taste of fat. A better understanding of the altered reward system in obesity may open the door to a new era for the diagnosis, management and treatment of this disease.

Reduced Fat Taste Sensitivity in Obese Japanese Patients and Its Recovery after a Short-Term Weight Loss Program

Fat taste has recently attracted attention as the 'sixth taste.' However, the relationship between fat and sweet taste in Japanese obesity has not yet been examined, and no reports have ascertained whether improvement of fat taste can be obtained by weight loss. Patients were recruited into obesity group (BMI≥30 kg/m²; n=15) or control group (BMI<25 kg/m²; n=11). They answered a questionnaire on smoking, eating behavior, lifestyle, and food frequency, and their taste thresholds were measured (fat, umami, and sweet). The obesity group was tested twice (on admission and before discharge). They showed several eating behavior abnormalities, higher total energy intake, and less physical activity. There were some gender differences: physical inactivity was more prominent in females, and high total energy intake in males, which correlates with fat taste rank. Fat taste rank was significantly higher in obesity group, whereas taste rank of umami and sweet were not significantly different. Gender-specific analysis of fat taste rank revealed only male obesity showed significant difference. Reduced sensitivity of fat may be specific to male gender or obesity by overeating, but not by physical inactivity. Multiple logistic regression analysis revealed that fat taste was a factor relevant to obesity. Fat taste significantly improved after a weight loss program, with average duration of 11.3 d. Japanese obese people, especially males and those who are obese by overeating, have reduced sensitivity to fat taste. This can be recovered by even a short-term weight loss program.

The prevalence of constipation and its relation to sweet taste preference among patients receiving methadone maintenance treatment

BACKGROUND

Preference for sweet-tasting foods, weight gain, and constipation characterize patients receiving methadone maintenance treatment (MMT). The prevalence of constipation in MMT and its relation to preference for sweet taste and body mass index (BMI) are undetermined.

METHODS

A random sample of 83 patients was interviewed for constipation with the Patient Assessment Constipation Quality of Life (PAC-QOL) questionnaire. They rated taste intensity and reward of sweet, salty, and sour solutions by means of a nine-point Likert scale. Data on their BMI, drugs in urine, methadone dose, and serum levels were analyzed.

RESULTS

Forty-two patients reported minimum to severe constipation. They characterized as having longer durations of opioid usage before MMT and worse sleep quality than non-constipated patients (logistic regression). Constipation intensity was inversely correlated with duration in MMT and linearly correlated with the Patient Assessment Constipation Quality of Life score. Patients with constipation rated reward to sweet taste significantly higher with no differences in taste intensity compared to non-constipated patients. Patients with high methadone serum levels (≥750 ng/mL) rated taste intensity significantly lower compared to those with normal methadone serum levels (<750 ng/mL), and the lowest rates were reported among patients with no constipation and high methadone serum levels.

CONCLUSIONS

Constipation was highly prevalent among MMT patients and associated with poor sleep and lower quality of life. The relation to preference for sweets, as reflected by higher reward rating, strongly supports the need for nutritional intervention to alleviate constipation symptoms and improve quality of life and sleep.

Linking categorical models for prediction of pleasantness score using individual predictions of sweetness and creaminess: An advancement of categorical modeling

The aim of this work was to develop and evaluate approaches of linked categorical models using individual predictions of probability. A model was developed using data from a study which assessed the perception of sweetness, creaminess, and pleasantness in dairy solutions containing variable concentrations of sugar and fat. Ordered categorical models were used to predict the individual sweetness and creaminess scores and these individual predictions were used as covariates in the model of pleasantness response. The model using individual predictions was compared to a previously developed model using the amount of fat and sugar as covariates driving pleasantness score. The model using the individual prediction of odds of sweetness and creaminess had a lower variability of pleasantness than the model using the content of sugar and fat in the test solutions, which indicates that the individual odds explain part of the variability in pleasantness. Additionally, simultaneous and sequential modeling approaches were compared for the linked categorical model. Parameter estimation was similar, but precision was better with sequential modeling approaches compared to the simultaneous modeling approach. The previous model characterizing the pleasantness response was improved by using individual predictions of sweetness and creaminess rather than the amount of fat and sugar in the solution. The application of this approach provides an advancement within categorical modeling showing how categorical models can be linked to enable the utilization of individual prediction. This approach is aligned with biology of taste sensory which is reflective of the individual perception of sweetness and creaminess, rather than the amount of fat and sugar in the solution.