Influence of PROP taster status and maternal variables on energy intake and body weight of pre-adolescents.

Genetic taste blindness to the bitterness of 6-n-propylthiouracil (PROP) may be a marker for increased energy intake and body weight. This hypothesis has not been tested in pre-adolescent children. This study determined if non-taster children would report higher energy intakes and maintain higher body weights than taster children. Maternal variables which are known to influence food intake and body weight during childhood were also considered including maternal weight, maternal restraint and disinhibition and child feeding practices. Sixty-five children with a mean age of 9.0+/-0.2 years participated. They completed a 3-day diet recall for the estimation of daily energy and macronutrient intakes. BMI (mothers) and BMI%-for-age (children) were calculated from measured heights and weights. Non-taster children reported higher daily energy intakes than super-taster children (p < or = 0.05), but no differences in macronutrient selection were observed. Also, children of disinhibited mothers reported higher daily energy intakes than children of mothers who were not disinhibited (p < or = 0.05). However, these variables did not predict children's body weight. Rather, regression modeling (R2 = 0.59; p < or = 0.0001) revealed that restriction, concern for child weight and maternal BMI were positive predictors of children's BMI%-for-age and pressure to eat was a strong negative predictor (p-value range = 0.02-0.004). PROP status was not a predictor of body weight in these children. These results suggest that in pre-adolescent children, current energy intakes were negatively related to children's PROP status and positively related to maternal disinhibition. However, BMI%-for-age, a measure of long-term energy balance, was related to child feeding practices and maternal BMI.

Adiposity in middle-aged women is associated with genetic taste blindness to 6-n-propylthiouracil.

OBJECTIVE: Taste blindness to the bitterness of 6-n-propylthiouracil (PROP) may be a genetic marker for food preferences and dietary choices that ultimately influence body weight. A previous study in middle-aged women showed that those who were taste blind to PROP (i.e., nontasters) had higher BMIs than those with the greatest sensitivity to PROP (i.e., supertasters). This study tested the hypothesis that the nontaster phenotype was associated with greater adiposity in middle-aged women. RESEARCH METHODS AND PROCEDURES: Forty women with a mean BMI of 26.6+/-1.3 kg/m2 and a mean age of 41.8+/-1.8 years were recruited from the local community. They were classified as nontasters (n=8), medium tasters (n=18), or supertasters (n=14) of PROP using a filter paper screening procedure. Anthropometric measures included height, weight, body fatness, triceps skinfold thickness, and waist circumference. Dietary restraint and disinhibition were also measured to assess cognitions associated with body weight. RESULTS: BMI was 6.2 units higher in nontaster women compared with supertaster women (29.7+/-0.9 vs. 23.5+/-0.9, respectively; p<0.05). Body fatness (p<0.01) and triceps skinfold thickness (p<0.05) were also higher in these women. Waist circumference showed a trend in the appropriate direction. Although disinhibition was associated with greater adiposity, the relation between PROP status and adiposity was not altered after controlling for disinhibition. DISCUSSION: The PROP nontaster phenotype was strongly associated with several measures of adiposity in middle-aged women. These data confirm our previous findings and suggest that the PROP polymorphism may be a reliable indicator of weight gain susceptibility.