Sweet taste and intake of sweet foods in normal pregnancy and pregnancy complicated by gestational diabetes mellitus

Gustatory and olfactory shifts during pregnancy and the postpartum period: A systematic review and meta-analysis

Pregnancy is a transformative phase marked by significant behavioral and physiological changes. Substantial changes in pregnancy-related hormones are thought to induce changes in chemosensory perception, as often observed in non-human animals. However, empirical behavioral research on pregnancy-related olfactory or gustatory changes has not yet reached a consensus. This PROSPERO pre-registered systematic review and meta-analysis evaluated published data of olfactory and gustatory changes in pregnant individuals, across the three pregnancy trimesters and postpartum period. Our comprehensive search strategy identified 20 relevant studies, for inclusion in the meta-analysis. The meta-analysis revealed that pregnant individuals, regardless of trimester, performed significantly poorer in terms of odour identification, however, no difference was detected between non-pregnant controls and women postpartum. Additionally, pregnant women in the second and third trimester rated olfactory stimuli to be more intense. A slight decline in odour pleasantness ratings was observed amongst those in the second trimester. No major difference was observed between pregnant and non-pregnant subjects in terms of gustatory functions, except the first trimester appeared to be associated with increased pleasantness for the sweet taste. Post-hoc meta-regression analyses revealed that pregnancy stage was a significant predictor for observed effect size for odour intensity ratings, but not for odour identification scores. These findings provide valuable insights into the interplay between pregnancy and chemosensory perception, highlighting systematic physiological changes due to pregnancy. Healthcare providers can also utilize the knowledge of sensory shifts to better support pregnant women in making appropriate dietary choices, managing sense-related discomfort, and leading to potential sensory interventions. Overall, this research enhances our comprehension of sensory shifts during pregnancy, benefiting maternal health and pregnancy-related care.

Examining the role of olfaction in dietary choice

Obesity is frequently caused by calorie-rich dietary choices across the animal kingdom. As prandial preference toward a high-fat diet develops in mice, an anti-preference or devaluation of a nutritionally balanced but less palatable standard chow diet occurs concomitantly. Although mechanistic insights underlying devaluation have been observed physiologically in the brain, it is unclear how peripheral sensory processing affects food choice. Because olfactory cues and odor perception help coordinate food preference and intake, we determine the role of smell in the targeted consumption of a high-fat diet and simultaneous devaluation of a standard chow diet. Using inaccessible food and loss-of-function manipulations, we find that olfactory information is neither sufficient nor necessary for both the acute and chronic selection of high-fat diet and coincident diminished value of standard diet. This work suggests alternative means are behind the immediate and sustained consumption of high-fat diet and concurrent standard diet devaluation.

Olfaction is considered integral to food choice and preference formation. Boone et al. use a behavioral approach to determine the salience of olfactory cues in diet selection. They find that olfaction is neither sufficient nor required for both high-fat-diet preference and standard diet devaluation.

Determinants of Sweetness Preference: A Scoping Review of Human Studies

Factors associated with sweetness preference are multi-faceted and incredibly complex. A scoping review was undertaken to identify determinants of sweetness preference in humans. Using an online search tool, ProQuest ™, a total of 99 publications were identified and subsequently grouped into the following categories of determinants: Age, dietary factors, reproductive hormonal factors, body weight status, heritable, weight loss, sound, personality, ethnicity and lifestyle, previous exposure, disease, and 'other' determinants. Methodologies amongst studies were heterogenous in nature (e.g., there was variability across studies in the sweetness concentrations tested, the number of different sweetness concentrations used to assess sweetness preference, and the methods utilized to measure sweetness preference), rendering interpretation of overall findings challenging; however, for certain determinants, the evidence appeared to support predictive capacity of greater sweetness preference, such as age during certain life-stages (i.e., young and old), being in a hungry versus satiated state, and heritable factors (e.g., similar sweetness preferences amongst family members). Recommendations for the design of future studies on sweetness preference determinants are provided herein, including an "investigator checklist" of criteria to consider.

Influence of GDM Diagnosis and Treatment on Weight Gain, Dietary Intake and Physical Activity in Pregnant Women with Obesity: Secondary Analysis of the UPBEAT Study

Obesity during pregnancy is associated with the development of gestational diabetes (GDM). This study aimed to assess if the result of an oral glucose tolerance test (OGTT) for GDM influences health (diet and physical activity) behaviours of pregnant women with obesity. In total, 1031 women who participated in the UK Pregnancies Better Eating and Activity Trial (UPBEAT) of a lifestyle intervention from early pregnancy were included. Changes in weight gain, dietary intake and physical activity following an OGTT undertaken between 27+0 and 28+6 weeks' and 34 and 36 weeks' gestation were examined using linear regression with appropriate adjustment for confounders. Obese women without GDM (IADPSG criteria) gained 1.9 kg (95% CI -2.2, -1.5, p < 0.001) more weight than women with GDM. Women with GDM demonstrated greater reductions in energy (-142kcal, 95%CI -242.2, -41.9, p = 0.006), carbohydrate intake (-1.5%E 95%CI -2.8, -0.3, p = 0.016) and glycaemic load (-15.2, 95%CI -23.6, -6.7, p < 0.001) and a greater increase in protein intake (2%E, 95%CI 1.3, 2.7, p < 0.001), compared to women without GDM. Trial intervention allocation did not influence any associations observed. The findings emphasise the need for strategies to optimise the health behaviours of pregnant women with obesity, following a negative OGTT for GDM.

Differences in food intake and genetic variability in taste receptors between Czech pregnant women with and without gestational diabetes mellitus

PURPOSE

Gestational diabetes mellitus (GDM) represents the most frequent metabolic disorder in pregnancy. Since dietary intake plays an important role in obesity and type 2 diabetes development, it is likely to be for the susceptibility to GDM too. Food preferences, driving partly the diet composition, are changing during pregnancy. Taste and genetic variability in taste receptors is an important factor in determining food preferences. Aims of our study were (1) to characterize dietary habits of pregnant women and to find possible differences in food preferences between healthy pregnant women and those with GDM and (2) to ascertain possible association of several single nucleotide polymorphisms (SNPs) in taste receptor (TR) genes with GDM.

METHODS

A total of 363 pregnant women (293 with GDM and 70 with physiologic pregnancy) were included in the study. Dietary pattern spanning the period of approx. 6 months preceding the time of GDM screening was assessed using a semi-quantitative food frequency questionnaire. A total of five SNPs in TR genes were selected for genotyping based on their functionality or previous associations.

RESULTS

Women with GDM exhibited significantly more frequent meat consumption (esp. poultry, pork and smoked meat), dairy products and sweet beverages consumption. The legumes consumption was found to be inversely correlated with fasting glycaemia (P = 0.007, Spearman). CC genotype in TAS2R9 gene (SNP rs3741845) was significantly associated with GDM (P = 0.0087, Chi-square test).

CONCLUSIONS

Our study showed differences in dietary intake of selected food items between healthy pregnant women and those with GDM and genetic association of bitter taste receptor allele with GDM.

Nutritional and clinical associations of food cravings in pregnancy

BACKGROUND

Cravings in pregnancy are considered to alter dietary intake; however, the nutritional consequences are unknown. The present study aimed to investigate the prevalence of food cravings in pregnancy, and their contribution, as a potentially modifiable determinant of weight gain and the development of obesity in pregnancy.

METHODS

Healthy pregnant women were participants in the Belfast cohort of the Hyperglycaemia and Adverse Pregnancy Outcome study (HAPO), a prospective observational study examining maternal glycaemia and pregnancy outcome. Diet was assessed at an average of 29 weeks of gestation using a self-administered validated food frequency questionnaire over the previous 2 weeks that included questions on food cravings experienced at any time during pregnancy. Clinical measurements collected included, height, weight, blood glucose and neonatal outcomes. Mean daily nutrient intakes were analysed with appropriate software.

RESULTS

Food cravings were reported by 39% (n = 635) of women, with sweet foods, fruit and dairy products most frequently consumed. Those who craved foods had a higher mean (SD) energy intake [9721 (3016) kJ] (P = 0.002) even when under-reporters were removed [10131 (2875) kJ] (P = 0.008). However, no differences were found in nutrient or food intake between groups when adjusted for energy. Similarly, no differences were observed between groups and glycaemic control, anthropometric measurements or offspring outcome measures.

CONCLUSIONS

Cravings commonly occur in pregnancy and contributed to a small increase in energy intake; however, this did not impact on overall dietary intake, nor was it associated with excessive gestational weight gain, maternal glycaemia or offspring outcome measurements.

Early Pregnancy Cravings, Dietary Intake, and Development of Abnormal Glucose Tolerance

BACKGROUND

Little is known about the relationships between pregnancy cravings, maternal diet, and development of abnormal glucose tolerance.

OBJECTIVES

We examined relationships of pregnancy cravings with dietary intake and risk of developing isolated hyperglycemia (IH), impaired glucose tolerance (IGT), or gestational diabetes (GDM) later in pregnancy.

DESIGN/SETTING

Among 2,022 mothers in Project Viva, a prospective birth cohort recruited from medical practices in eastern Massachusetts between 1999 and 2002, we assessed type of pregnancy craving based on self-report at mean gestation of 10.9 weeks.

MAIN OUTCOME MEASURES

The outcomes were cross-sectional dietary intake from a food frequency questionnaire and incident IH, IGT, or GDM determined by glucose tolerance screening at 26 to 28 weeks.

STATISTICAL ANALYSES PERFORMED

We used linear regression to analyze the cross-sectional relationships between pregnancy cravings and dietary intake and multinomial logistic regression to analyze the prospective relationships among pregnancy cravings and development of IH, IGT, or GDM.

RESULTS

During the first trimester, 443 (22%) women craved sweets, 225 (11%) craved salty foods, 261 (13%) craved savory foods, and 100 (4.9%) craved starchy foods. Sweet cravings were associated with increased intake of sucrose (1.9 g/day; 95% CI 0.1 to 3.7), total fat (1.5 g/day; 95% CI 0.1 to 2.9), and saturated fat (0.8 g/day; 95% CI 0.2 to 1.4); salty cravings were associated with increased fiber (0.7 servings/day; 95% CI -0.1 to 1.6); savory cravings were associated with increased n-3 fatty acids (0.10 g/day; 95% CI 0.02 to 0.17); and starchy cravings were associated with increased carbohydrates (8.0 g/day; 95% CI 0.3 to 15.7) and decreased total fat (-2.6 g/day; 95% CI -5.2 to -0.1). Salty cravings were associated with lower risk of GDM (adjusted odds ratio 0.34, 95% CI 0.12-0.97).

CONCLUSIONS

New cravings in the first trimester of pregnancy were associated with dietary intake. Craving salty foods may predict reduced risk of developing GDM, whereas craving sweet food does not appear to alter one's risk.

Decreased sucrose preference in patients with type 2 diabetes mellitus

AIMS

Increased sugar consumption may adversely affect glycemic control in patients with diabetes. Although patients with diabetes are generally thought to prefer sweet tastes, few data are available on the sucrose preference in these individuals. The aim of the present study was to evaluate sucrose preference in patients with type 2 diabetes in comparison with subjects without diabetes.

METHODS

Sucrose preference was assessed in 200 subjects (100 type 2 diabetes patients and 100 age-, sex- and body mass index (BMI)-matched control subjects). Sucrose preference was evaluated together with sucrose perception (i.e., sucrose sensitivity). Clinical and biochemical factors affecting sucrose taste were also analyzed.

RESULTS

Participants with type 2 diabetes preferred lower sucrose concentrations compared with control subjects (p=0.001), although they had a less sensitive palate for sucrose compared with subjects without diabetes (p=0.012). Individual sucrose preference demonstrated a negative relationship with sensitivity to sucrose in control subjects. Notably, this relationship between sucrose preference and sensitivity was completely absent in participants with type 2 diabetes. Male patients with diabetes demonstrated a higher sucrose preference compared with female patients. There were no significant correlations between sucrose preference and glycemic control, duration of diabetes, or anti-diabetic medications.

CONCLUSIONS

Participants with type 2 diabetes demonstrate a lower preference for sweet tastes than control subjects despite their decreased perception of sucrose. Reduced sucrose preference is not associated with better glycemic control in individuals with diabetes.

Adverse effects of high-intensity sweeteners on energy intake and weight control in male and obesity-prone female rats

The use of high-intensity sweeteners has been proposed as a method to combat increasing rates of overweight and obesity in the human population. However, previous work with male rats suggests that consumption of such sweeteners might contribute to, rather than ameliorate, weight gain. The goals of the present experiments were to assess whether intake of high-intensity sweeteners is associated with increased food intake and body weight gain in female rats; to evaluate whether this effect depends on composition of the maintenance diet (i.e., standard chow compared with diets high in energy, fat, and sugar [HE diets]); and to determine whether the phenotype of the rats with regard to propensity to gain weight on HE diets affects the consequences of consuming high-intensity sweeteners. The data demonstrated that female rats fed a low-fat, standard laboratory chow diet did not gain extra weight when fed yogurt dietary supplements sweetened with saccharin compared with those fed glucose-sweetened dietary supplements. However, female rats maintained on a "Westernized" diet high in fat and sugar (HE diet) showed significant increases in energy intake, weight gain, and adiposity when given saccharin-sweetened compared with glucose-sweetened yogurt supplements. These differences were most pronounced in female rats known to be prone to obesity prior to the introduction of the yogurt diets. Both selectively bred Crl:OP[CD] rats and outbred Sprague-Dawley rats fed an HE diet showing high levels of weight gain (diet-induced obese [DIO] rats) had increased weight gain in response to consuming saccharin-sweetened compared with glucose-sweetened supplements. However, in male rats fed an HE diet, saccharin-sweetened supplements produced extra weight gain regardless of obesity phenotype. These results suggest that the most negative consequences of consuming high-intensity sweeteners may occur in those most likely to use them for weight control, females consuming a "Westernized" diet and already prone to excess weight gain.

Prediction of nutritive intake energy and substrates of Czech pregnant women

OBJECTIVE

Equations linking nutritional intake of energy and substrates (NIES) to anthropometry during pregnancy are currently unknown. The aim of this longitudinal study was to determine the predictive equations for NIES as an expression of dietary patterns.

METHODS

In total, 152 randomly recruited healthy pregnant Czech women (non-smokers, non-users of long-term medications or abusers of alcohol or drugs, normoglycemic, euthyroid, and non-anemic) were divided into two cohorts: group 1 (n = 31) was used for the determination of equations for NIES during pregnancy, and group 2 (n = 121) for cross-validation of these equations. In both study groups, anthropometry was measured and resting energy expenditure obtained by indirect calorimetry after 12 h of fasting during four phases of pregnancy. NIES was evaluated from self-reported dietary intake records over 7 d.

RESULTS

Strong relations were found between NIES and anthropometric parameters, especially the difference between pregnancy body weight and ideal body weight. By correlation analysis and linear regression, new predictive equations were derived for NIES during pregnancy using the difference between pregnancy body weight and ideal body weight. A high concordance was observed between values from the predictive equations and the actual assessed values of NIES in group 2.

CONCLUSION

The proposed equations for nutritional intake of energy, protein, and fats have a reasonable prediction power during pregnancy in relation to physiologic birth outcome.

Evaluation of gustatory function in patients with diabetes mellitus type 2

OBJECTIVES

The aim of this study was to evaluate the gustatory function of patients with diabetes mellitus type 2 and to compare gustatory appreciation on right and left sides of the tongue and soft palate.

STUDY DESIGN

The study group was composed of 40 controlled and 40 uncontrolled diabetes mellitus type 2 patients. A group of 40 age- and gender-matched healthy control subjects were also evaluated. Gustatory function was tested by administering a whole-mouth above-threshold test and spatial taste test using sucrose, sodium chloride (NaCl), citric acid, and quinine hydrochloride solutions. Statistical analysis was performed using 1-way ANOVA and Student t test.

RESULTS

Taste impairment was found in the controlled and uncontrolled diabetic patients relative to healthy control subjects (P < .0001). A highly significant difference was noticed for sweet (P = .00001) and sour (P = .00002) tastes. For salt taste, a significant difference was found (P = .001). Hypogeusia was reported among 50 (62.5%) of the diabetic patients versus 5 (12.5%) of control subjects (P < .0001). Ageusia to sweet was found in 6 uncontrolled diabetic patients (P < .0001). For almost all 120 subjects, taste sensitivity was found to be equivalent on left and right sides of the tongue and soft palate.

CONCLUSION

Type 2 diabetic patients had a blunted taste response for sweet followed by sour and salt tastes. This taste abnormality may influence the choice of nutrients, with a preference for sweet-tasting foods, thereby exacerbating hyperglycemia.

Nutritional status alters saccharin intake and sweet receptor mRNA expression in rat taste buds

Sweet taste usually signifies the presence of caloric food. It is commonly accepted that a close association exists among sweet taste perception, preference, and nutritional status. However, the mechanisms involved remain unknown. To investigate whether nutritional status affects the preference for palatable solutions and alters sweet taste receptor gene expression in rats, we measured saccharin intake and preference using a two-bottle preference test, and changes in body weight, plasma leptin levels, and gene expression for the sweet taste receptor in taste buds in high-fat diet-induced obese rats and chronically diet-restricted rats. We found that the consumption and preference ratios for 0.01 and 0.04 M saccharin were significantly lower in the high-fat diet-induced obese rats than in the normal diet rats, while the serum leptin levels were markedly increased in obese rats. Consistent with the changes in saccharin intake, the gene expression level of the sweet taste receptor T1R3 was significantly decreased in the high-fat diet-induced obese rats compared with the control rats. By contrast, the chronically diet-restricted rats showed remarkably enhanced consumption and preference for 0.04 M saccharin. The serum leptin concentration was decreased, and the gene expression of the leptin receptor was markedly increased in the taste buds. In conclusion, our results suggest that nutritional status alters saccharin preference and the expression of T1R3 in taste buds. These processes may be involved in the mechanisms underlying the modulation of peripheral sweet taste sensitivity, in which leptin plays a role.

Taste and weight: is there a link?

Investigations of the relations between taste perception and obesity have concentrated largely on sweet and bitter tastes, with little work on the "savory" tastes-salt and glutamate-and very little work on sour taste. This article briefly reviews current understanding of the relations between the ability to taste different tastes (ie, taste threshold for sweet, bitter, sour, salt, and umami) and body mass. Obese children and adolescents show a disturbance in some tastes, with reported reductions in sweet and salt thresholds. Observations on relations between sweet taste threshold and obesity are contradictory; literature discrepancies may depend on the techniques used to evaluate taste. Obese women, however, report higher intensities of monosodium glutamate perception. Taste thresholds have been reported to be raised (bitter and sour), lowered (salt), or unchanged (sweet) in obese adults. Taste perceptual changes (threshold, intensity) in obesity are complex and may be different in obese men and women and in adults and children. Very little is currently known about the relations between savory tastes-salt and umami-and body weight, and these areas merit further study.

Changes in sweet taste across pregnancy in mild gestational diabetes mellitus: relationship to endocrine factors

Gestational diabetes mellitus (GDM) is glucose intolerance diagnosed during pregnancy. Previous work suggested that women with GDM showed exaggerated preferences for sweet taste, but data were limited to a single time point during pregnancy. This study longitudinally assessed sweet taste changes across pregnancy in women who developed GDM (n = 15) as compared with women with normal glucose tolerance (NGT; n = 93) and nonpregnant controls (n = 19). A second objective was to relate sweet taste changes in GDM to fasting leptin and insulin profiles. Following an overnight fast, subjects evaluated strawberry-flavored milks varying in sucrose and fat content, as well as glucose solutions. Evaluations were made at 3 time points during pregnancy and during early postpartum. At 34-38 weeks gestation, women with GDM gave higher liking ratings to moderately sweetened (5% and 10% sucrose) strawberry milks than women with NGT. These differences were not related to alterations in the perception of the samples. At 24-28 weeks gestation, and in women with GDM only, fasting insulin was correlated with liking of the glucose solutions (R(2) = 0.63, P = 0.004) and fasting leptin was correlated with sweetness liking of the 10% sucrose milk (R(2) = 0.42, P = 0.017). These data suggest that women with GDM exhibit higher liking ratings for a sweet fat milk drink late in pregnancy. Also, higher hedonic ratings for sweet taste in GDM may be related to elevated leptin and insulin concentrations at midpregnancy. GDM may increase the desire for sweet taste that could influence dietary management of this disease.

Olfactory and gustatory sensory changes to tobacco smoke in pregnant smokers

Models of smoking behavior change include addiction, social, and behavioral concepts. The purpose of this study was to explore the prevalence of two biologic factors, olfactory and gustatory responses to tobacco smoke, as potentially powerful contributors to smoking behavior change among pregnant women. Data were obtained from 209 pregnant smokers. The majority of women reported olfactory (62%) and gustatory (53%) aversions to tobacco. Aversions first appeared during the first trimester of pregnancy. Women who experienced olfactory aversions were more likely also to experience gustatory aversions. Olfactory aversions were associated with women smoking less. Aversions to tobacco smoke are common among pregnant smokers, are associated with women smoking less, and could help explain pregnant women's smoking patterns.

Obese OLETF rats exhibit increased operant performance for palatable sucrose solutions and differential sensitivity to D2 receptor antagonism

CCK-1-receptor-deficient Otsuka Long-Evans Tokushima fatty (OLETF) rats are hyperphagic and exhibit a greater preference for sucrose compared with lean controls [Long-Evans Tokushima Otsuka (LETO)]. To directly assess motivation to work for sucrose reward in this model of obesity and type 2 diabetes, we examined the operant performance of OLETF rats at nondiabetic and prediabetic stages (14 and 24 wk of age, respectively) on fixed-ratio (FR) and progressive-ratio (PR) schedules of reinforcement. To evaluate the involvement of dopamine systems, the effects of the D1 receptor antagonist SCH23390 (100 and 200 nmol/kg ip) and the D2 receptor antagonist raclopride (200 and 400 nmol/kg ip), were also tested on PR responding for sucrose. Compared with age-matched LETO rats, 14-wk-old OLETF rats emitted more licks on the "active" empty spout operant on the FR-10 schedule of reinforcement to obtain 0.01 M and 0.3 M sucrose and completed higher ratio requirements on the PR schedule to gain access to 0.3 M and 1.0 M sucrose. At 24 wk, this effect was limited to 1.0 M sucrose. Both antagonists were potent in reducing operant responding to 0.3 M sucrose in both strains at both ages, and there was no strain effect to SCH23390 at either age. OLETF rats, on the other hand, showed an increased sensitivity to the higher dose of raclopride, resulting in reduced responding to sucrose reinforcement at 24 wk. Taken together, these findings provide the first direct evidence for an increased motivation for sucrose reward in the OLETF rats and suggest altered D2 receptor regulation with the progression of obesity and prediabetes.

Nutrient intake of women with and without gestational diabetes with a specific focus on fatty acids

OBJECTIVE

Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Women with GDM are commonly given dietary advice that broadly focuses on a reduction of total energy and fat consumption. We compared nutrient intake and specifically fatty acids of women with GDM who had received individualized nutritional counseling with those of non-diabetic women who did not.

METHOD

Women with GDM (n=44) and healthy pregnant women (n=44) with uncomplicated singleton pregnancies were recruited during the third trimester. Women with GDM were given consultation on diet, health, and macronutrient content of foods commonly consumed by the individual. The non-diabetic group did not receive any dietary advice. Both groups were asked to keep a detailed record of all of foods and fluid consumed over a 4-d period.

RESULTS

After dietary counseling, the GDM group had lower intakes of energy (P<0.05), refined sugar (P<0.0001), total and saturated fats (P<0.0001), and monounsaturated (P<0.01) and trans (P<0.0001) fatty acids and higher levels of docosahexaenoic acid and fiber (P<0.05) compared with the non-diabetic group.

CONCLUSIONS

Individualized dietary advice was associated with a lower consumption of the target nutrients in women with GDM. Another benefit of the advice was a slight increase in intake of eicosapentaenoic and docosahexaenoic acids, although consumption of omega-3 fatty acids by both groups was well below the recommendations for pregnancy. There is evidence that docosahexaenoic acid modulates insulin resistance and that it is vital for neurovisual development. We suggest that dietary management for women with GDM should foster the current recommendations for essential fatty acids in pregnancy.

A model for postpartum smoking resumption prevention for women who stop smoking while pregnant

Behavior change models and theories have been useful in our efforts to help people stop smoking. However, models that were developed for the general population do not always fit special populations such as pregnant women. Many women stop smoking while pregnant, but most resume smoking after giving birth. To help women who stop smoking while pregnant to stay smoke-free, a model for tailoring a smoking resumption-prevention intervention to the special needs of pregnant and postpartum women is proposed. The intervention begins during pregnancy, continues postpartum, and addresses pregnancy and parenting contextual factors in women's lives. The model is based on motivational theory and includes conducting patient assessments, developing risk profiles, triaging women to different levels of intervention intensity, and matching intervention strategies to women's risk profiles.

Food choices of low-income women during pregnancy and postpartum

OBJECTIVES

The purpose of this study was to examine dietary behavior during pregnancy and postpartum in a multiethnic sample of low-income women.

SUBJECTS

Participants were 149 Medicaid-qualified women (30% white, 24% African American, and 46% Hispanic; median age, 22 years).

DESIGN

Subjects were recruited into a longitudinal cohort design 0 to 1 days following delivery. Dietary choices during pregnancy and the first 6 months postpartum were assessed via validated food frequency questionnaires administered at 6 weeks and 6 months postpartum, respectively.

STATISTICAL ANALYSES PERFORMED

Frequencies and means were used for descriptive purposes. Paired and independent sample t tests were used for continuous variables; chi 2 and McNemar tests were used for categorical variables.

RESULTS

In all subjects, mean daily servings of grains (7.4 vs 6.2, P <.004), vegetables (2.5 vs 2.0, P <.002), and fruit (3.4 vs 1.7, P <.001) declined following childbirth, while the percentage of energy from fat (37.3% vs 38.4%, P <.023) and added sugar (14.4% vs 16.4%, P <.019) increased. Women who breastfed their infants at 6 months postpartum reported lower intakes of total fat (34.2% vs 37.9%, P <.005) during pregnancy and higher fruit (2.2 vs 1.6, P <.05) and vegetable (2.6 vs 1.8, P <.02) intakes in postpartum than those who bottle-fed. Also, a greater proportion of lactating than nonlactating women (66.7% vs 36.9%, P <.05) met recommendations for fruit intake during pregnancy.

CONCLUSIONS

The findings suggest that the transition from pregnancy to postpartum may be associated with a negative impact on dietary behavior that could compromise nutritional status in low-income women.

Deficient dietary intake of vitamin E in patients with taste and smell dysfunctions: is vitamin E a cofactor in taste bud and olfactory epithelium apoptosis and in stem cell maturation and development?

OBJECTIVES

We reviewed dietary intake of several nutrients in a large group of patients with taste and smell dysfunction, compared intake of these nutrients with standard values, and recognized that intake of vitamin E was significantly less than that of most other nutrients. Based on this observation we attempted to develop an hypothesis of the possible role vitamin E might play in these sensory disorders.

METHODS

Vitamin E intake was measured in 250 patients with taste and smell dysfunctions.

RESULTS

Intake of the vitamin was 3.2 +/- 0.2 mg/d (mean +/- standard error of the mean), or 36 +/- 2% of the recommended daily allowance, an intake significantly below that considered adequate. This diminished intake occurred with normal intake of total calories; protein; fat; carbohydrate; several vitamins, including thiamin, niacin, and pyridoxine; and the trace metals zinc, copper, and iron.

CONCLUSIONS

Although specific relations between vitamin E intake and smell and taste dysfunctions are unclear, the non-antioxidant roles of vitamin E indicate that it is a factor in apoptosis, cellular signaling, and growth of various cell lines, suggesting that this vitamin may play a role in growth and development of stem cells in taste buds and olfactory epithelium.

Position of the American Dietetic Association: use of nutritive and nonnutritive sweeteners

Sweeteners elicit pleasurable sensations with (nutritive) or without (nonnutritive) energy. Nutritive sweeteners (eg, sucrose, fructose) are generally recognized as safe (GRAS) by the Food and Drug Administration (FDA), yet concern exists about increasing sweetener intakes relative to optimal nutrition and health. Dietary quality suffers at intakes above 25% of total energy (the Institutes of Medicine's suggested maximal intake level). In the United States, estimated intakes of nutritive sweeteners fall below this, although one in four children (ages 9 to 18 years) can surpass this level. Polyols (sugar alcohols), GRAS-affirmed or petitions filed for GRAS, add sweetness with reduced energy and functional properties to foods/beverages and promote dental health. Five nonnutritive sweeteners with intense sweetening power have FDA approval (acesulfame-K, aspartame, neotame, saccharin, sucralose) and estimated intakes below the Acceptable Daily Intake (level that a person can safely consume everyday over a lifetime without risk). By increasing palatability of nutrient-dense foods/beverages, sweeteners can promote diet healthfulness. Scientific evidence supports neither that intakes of nutritive sweeteners by themselves increase the risk of obesity nor that nutritive or nonnutritive sweeteners cause behavioral disorders. However, nutritive sweeteners increase risk of dental caries. High fructose intakes may cause hypertriglyceridemia and gastrointestinal symptoms in susceptible individuals. Thus, it is the position of The American Dietetic Association that consumers can safely enjoy a range of nutritive and nonnutritive sweeteners when consumed in a diet that is guided by current federal nutrition recommendations, such as the Dietary Guidelines for Americans and the Dietary References Intakes, as well as individual health goals. Dietetics professionals should provide consumers with science-based information about sweeteners and support research on the use of sweeteners to promote eating enjoyment, optimal nutrition, and health.

Genetic taste sensitivity to 6-n-propylthiouracil influences food preference and reported intake in preschool children

Adult tasters of 6-n-propylthiouracil (PROP) are more sensitive to bitter taste and fattiness in foods, and often show lower acceptance of foods that are high in these taste qualities. This study hypothesized that PROP taster children would show lower acceptance of these same foods. Sixty-seven preschool children were classified as PROP tasters (N = 43) or nontasters (N = 24) using a suprathreshold screening solution. Children rated acceptance of 10 bitter and/or fat-containing foods using a 5-pt. facial scale. Parents completed a food frequency questionnaire to estimate their child's intake. Taster children showed lower acceptance of raw broccoli and American cheese (p < or = 0 x 05). Taster-girls showed lower acceptance of full-fat milk than nontaster-girls (p < or = 0 x 05). This effect was not seen in boys. Nontasters reported more daily intake of discretionary fats than tasters (p < or = 0 x 05), an effect largely due to nontaster-girls, in whom reported intake was 2--3 more servings per day than taster-girls, and boys of both groups. These data suggest that PROP taste sensitivity plays a role in acceptance of certain bitter cruciferous vegetables and cheese by young children. In addition, taster group differences in acceptance of full-fat milk and intake of discretionary fats seen in girls, suggest that gender-specific environmental factors might interact with genetics to influence fat preferences.

Reproductive Immunosuppression and Diet

Pregnancy sickness, a suite of "symptoms" that frequently co-occur during pregnancy, may be an adaptation providing behavioral prophylaxis against infection. Maternal immunosupression, necessary for tolerance of the fetus, results in gestational vulnerability to pathogens. Throughout the period of maximal vulnerability, dietary behavior is significantly altered via changes in nausea susceptibility and olfaction and the development of marked aversions and cravings. Of food types, meat is both the most likely to carry pathogens and the principal target of gestational aversions and pregnancy taboos. Because meat was prominent in ancestral human diets but hygienic procedures that effectively eliminate the risk of meat-borne infection are recent, such pathogens likely constituted a source of selective pressure on pregnant females throughout human history. Both the relatively low protein and energy demands of the first trimester and the existense of nonmeat alternatives would have allowed for the evolution of time-limited gestational meat-avoidance mechanisms.Complementing these mechanisms, gestational cravings target substances that may influence immune functioning and affect the availability of iron in the gastro-intestinal tract, thereby limiting the proliferation of iron-dependent pathogens. Clinical and ethnographic findings are examined in light of these proposals, and directions for future research are outlined.