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Biomedical subjects

L L Birch

Publications and source records attributed to L L Birch.

At least 55 records · Page 3Linked to original sources
PubMed1993

The postingestive consequences of fat condition preferences for flavors associated with high dietary fat.

To investigate whether children acquire conditioned preferences for flavors associated with high dietary fat content, 27 3- and 4-year-old children participated in a series of 12 conditioning or mere exposure sessions. Following an overnight fast, children who participated in conditioning trials consumed fixed quantities of a flavored yogurt drink that on half the days was high in fat and energy (954 kJ, 18 g fat/150 g serving) or contained no fat (277 kJ, 0 g fat/150 g serving). Children in the conditioning group consumed 150 g servings, children in the mere exposure group tasted 16 g or less of these same stimuli. Preferences were assessed before and after conditioning when the children were hungry and also postconditioning when the children were satiated. Results provided evidence for conditioned preferences based on the postingestive consequences of dietary fat. Children in the conditioning group learned to prefer the high-density paired flavor over the low-density paired flavor, and increased their preference for the high-density paired flavor from pre- to postconditioning. Children in the mere exposure group showed positive shifts in preference for both the fat-free and the high-fat paired flavors. In the conditioning group, preferences for the high-fat flavor was depressed by satiety, whereas the preference of the mere exposure group did not vary with hunger state. Conditioned flavor preferences, based on the postingestive consequences of fat intake, may contribute to children's preferences for foods high in dietary fat.

Association Learning↗
PubMed1993

Effects of a nonenergy fat substitute on children's energy and macronutrient intake.

To determine whether children adjusted their energy intake in response to covert manipulations in the proportion of energy from dietary fat, 24-h food intake of 29 2- to 5-y-old children was measured over four 2-d blocks. In this within-subject crossover design, in the first three meals of the first day of each block, children consumed foods containing dietary fat or a nonenergy fat substitute, which provided 10% of total daily energy intake. Children compensated for the missing energy; cumulative energy intake differed by only 100 kJ over 2 d. Substitution for dietary fat reduced the percent of energy from fat from 38.7% to 36.4%. Children's intake at individual meals was highly variable (mean CV 24.7%) relative to the variability of total daily energy intake (CV = 8.6%). To produce this pattern, children adjusted energy intake across successive meals. Use of a fat substitute at 10% of energy from dietary fat did not significantly reduce 24-h energy intake.

Analysis of Variance↗
PubMed1993

Help me make it through the night: behavioral entrainment of breast-fed infants' sleep patterns.

The study objective was to investigate whether exclusively breast-fed infants could be taught to sleep through the night (defined from 12:00 AM to 5:00 AM) during the first 8 weeks of life. The design was short-term longitudinal, from the last trimester of pregnancy until the eighth week after birth. Twenty-six first-time parents and their newborn were randomly assigned to treatment and control groups (13 in each group). Treatment parents were instructed to offer a "focal feed" (between 10 PM and 12 AM) to their infants every night, to gradually lengthen intervals between middle-of-the-night feeds by carrying out alternative caretaking behaviors (eg, reswaddling, diapering, walking), and to maximize environmental differences between day and nighttime. All parents kept 72-hour diaries of their infants' feeding and sleeping patterns every week from birth to 8 weeks of age and rated their infants' temperament at birth and at 8 weeks. By 3 weeks, treatment infants showed significantly longer sleep episodes at night. By 8 weeks 100% of treatment infants were sleeping through the night compared to 23% of control infants. Treatment infants were feeding less frequently at night but compensated for the relatively long nighttime interval without a feed by consuming more milk in the early morning. Milk intake for 24-hour periods did not differ between groups. Treatment infants were rated as more predictable on Bates' Infant Characteristics Questionnaire. It is concluded that parents can have a powerful influence on the development of their infants' sleep patterns. Frequent night waking in breast-fed infants often results in early termination of lactation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1992

Tryptophan intake influences infants' sleep latency.

Formula-fed infants have depressed plasma tryptophan concentration relative to human milk-fed infants. Because tryptophan alters sleep-waking patterns in adults, a study was designed to determine whether additional dietary tryptophan could elevate plasma tryptophan concentrations of formula-fed infants to concentrations characteristic of human milk feeding and whether differences in plasma tryptophan or the ratio of plama tryptophan to the sum of the other plasma large neutral amino acids (tryptophan:LNAA) were of behavioral significance. Infants were fed a formula (13 g protein/L; whey:casein, 34:66) containing either 0, 294, 588 or 882 mumol/L of added tryptophan. Infants fed human milk or commercial formula (15 g protein/L; whey:casein, 18:82) were included for comparison. In formula-fed groups, plasma tryptophan was directly related to tryptophan intake (r = 0.46, P less than 0.0005). Infants fed commercial formula or the formula without added tryptophan had lower (P less than 0.001) plasma tryptophan compared with infants fed human milk. Only the infants fed the highest tryptophan formula had significantly higher plasma tryptophan:LNAA ratios than the other experimental groups, and these ratios were similar to those of infants fed human milk. The plasma tryptophan:LNAA ratios, not plasma tryptophan concentrations, were predictive of differences in the infants' sleep latency; infants fed formula containing the highest tryptophan had sleep latencies of 18.7 min, significantly shorter (P less than 0.05) than those of infants fed formulas containing less added tryptophan (27.7 min). Feeding infants formulas differing in tryptophan concentration produced differences in sleep latency, which could influence neurobehavioral developments.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1992

Children's preferences for high-fat foods.

Many high-fat foods are highly preferred by adults, and children soon acquire these preferences. The circumstances and mechanisms that contribute to establishing children's preferences for high-fat foods are the subject of this review.

Child↗
PubMed1991

The variability of young children's energy intake.

BACKGROUND: Research conducted in the 1930s showed that, given nutritious choices, children can select an adequate diet without adult supervision. Paradoxically, children grew well and were healthy despite patterns of intake at individual meals that were unpredictable and highly variable. METHODS: To investigate in more detail the energy intake of young children, we measured 24-hour food intake for 15 children, from two to five years of age, on six days. For each of the six days of the study, coefficients of variation were calculated for each child for each of the six meals and snacks (breakfast, lunch, dinner, and morning, afternoon, and evening snacks) and for total daily energy intake. RESULTS: The children's intake at individual meals was highly variable, but total daily energy intake was relatively constant for each child. The mean coefficient of variation for each child's energy intake at individual meals was 33.6 percent; in contrast, the mean coefficient of variation for each child's total daily energy intake was 10.4 percent. In most cases, high energy intake at one meal was followed by low energy intake at the next meal, or vice versa. CONCLUSIONS: Although children's food consumption is highly variable from meal to meal, daily energy intake is relatively constant, because children adjust their energy intake at successive meals.

Child↗
PubMed1991

Conditioned preferences: young children prefer flavors associated with high dietary fat.

In two experiments, 20 2-5-year-old children participated in a series of 8 conditioning trials to investigate whether they acquired conditioned preferences based on the fat content of a food. On different days, each child consumed fixed quantities of novelly flavored yogurts that were high or low in fat and energy density (220 or 110 kcal/serving). After conditioning, patterns of ad lib consumption data provided evidence of caloric compensation in response to the energy density differences in the preloads. Children consumed more following the low- than the high-fat preloads. Preference assessments, performed pre- and postconditioning, revealed conditioned flavor preferences based on fat content: children increased their preference for the high-density paired flavor, but no change in preference was noted for the low-density paired flavor. These data suggest that such conditioned flavor preferences based on energy density may be contributing to children's preferences for foods high in dietary fat.

Child, Preschool↗
PubMed1990

The scapegoat effect on food aversions after chemotherapy.

The effects of consuming a novel food (halva) versus a familiar food (cookies) before gastrointestinal (GI) toxic chemotherapy on patients' preference for familiar foods consumed after chemotherapy treatment were compared. The development of aversions to the novel and familiar foods was also assessed. Patients with a history of posttreatment nausea consumed either a novel or a familiar food before chemotherapy and were asked to keep a food record through the next breakfast and to rate their preference for these foods. Patients who consumed halva before treatment were significantly more likely to increase their ratings for foods consumed after chemotherapy than patients who consumed familiar cookies. Aversions to the novel food were significantly more frequent than aversions to the familiar food. These findings provide evidence that a novel but not a familiar food consumed before chemotherapy can act as a scapegoat to prevent items in the regular diet consumed after chemotherapy from decreasing in preference. Providing patients with a novel food before chemotherapy is a useful clinical intervention to reduce the likelihood of forming aversions to familiar foods consumed after chemotherapy.

Adult↗
PubMed1990

Control of intake by human-milk-fed infants: relationships between feeding size and interval.

Diurnal feeding behavior of 24 exclusively breast-fed infants was examined at 2, 4, 6, 8, and 12 weeks to assess whether milk intake at a feeding was related to previous (preprandial) or subsequent (postprandial) intervals between feedings. Amount of human milk consumed per feeding and intervals between feedings were measured over a 72-hr period. Correlation analyses revealed that volume of milk ingested at a feeding (meal size) was positively related to preprandial interval at all 5 ages (r = 0.39-0.47, p less than 0.0001). Meal size was likewise related, but not as strongly, to postprandial interval at 4 of the 5 time points examined (r = 0.17-0.25, p less than 0.01). Results of the correlational analyses revealed clear, consistent preprandial correlations, providing evidence for a reactive type feeding pattern among the solely breast-fed infants. Postprandial correlations, possibly reflect an anticipatory feeding pattern, were present but remained consistently low over the 3 months examined, providing little evidence of a developmental shift. This study provides a preliminary foundation for future longitudinal studies that address the regulation of food intake among infants.

Arousal↗
PubMed1990

Conditioned flavor preferences in young children.

In this experiment 11 children participated in a series of 8 pairs of conditioning trials in order to investigate the hypothesis that children could form conditioned flavor preferences based on caloric density. Unfamiliar drink flavors were used in these trials, and the drinks were either high in caloric density (155 kcal/150 ml) or low (less than 5 kcal/150 ml). Caloric density was altered by the addition of low glucose maltodextrin. Each child always had the same caloric density/flavor pairing throughout the conditioning trials. Each trial pair included one high and one low density preload, followed by ad lib consumption. These conditioning trials substituted for the children's regularly scheduled morning snack four days per week, one trial per day. Conditioning trials were given as a series of two-part snacks, consisting of fixed volumes of initially unfamiliar drinks, followed by the opportunity to eat a variety of foods ad lib. Two measures, obtained before and after conditioning, provided evidence for the formation of conditioned flavor preferences: 1) preference assessments, and 2) two-flavor choice tests. In addition, the ad lib consumption data indicated that the children were responsive to the caloric density manipulation, by consistently eating more following the low than the high density drink. The potential contribution of such acquired flavor preferences to the reduction of neophobia is discussed.

Child Development↗
PubMed1989

Children's food intake following drinks sweetened with sucrose or aspartame: time course effects.

In two experiments, 2-5-year-old children's responsiveness to caloric density cues was examined. In a preloading protocol, consumption of fixed volumes of drinks (205 ml in Experiment 1; 150 ml in Experiment 2), sweetened with sucrose, aspartame, aspartame plus low glucose maltodextrin, or a water control, was followed by ad lib consumption from among a variety of foods. Caloric drinks had about 90 kcal in Experiment 1, 65 kcal in Experiment 2. The delay interval between the preload and the ad lib consumption was 0, 30 or 60 minutes. In Experiment 1, 24 4- and 5-year-old children participated in only one delay interval, while in Experiment 2, all 20 2- and 3-year-old children were seen in all conditions. Results revealed evidence of caloric compensation, but no evidence of preload x time delay interaction. In both experiments, aspartame also produced a significant suppression of intake relative to water, primarily due to the pattern at 30 min following the preload. Across conditions, the suppression following aspartame was usually significantly less than that produced by the caloric sweet drinks, providing evidence for postingestive effects. In Experiment 1, suppression of intake was related to the children's preferences for the foods, not to macronutrient content; consumption of nonpreferred foods was most suppressed. Consumption of sweetened drinks as long as 1 hour prior to eating suppressed food intake, and this common feeding practice may also reduce dietary variety.

Aspartame↗
PubMed1989

Conditioned meal initiation in young children.

In two experiments the conditioning of meal initiation was investigated. Preschool children ate snacks repeatedly in the presence of visual and auditory cues (CS+). On other days, other visual and auditory cues (CS-) were presented in the absence of food. In the second experiment, location also served as a CS. To test for conditioned meal initiation, children were first fed a snack to ensure that they were sated. Immediately following this, on different days, food was presented in the presence of the CS+ or the CS- cues. Data on latency to eating and total consumption revealed evidence for conditioning, at least for children who could correctly identify which cues had and had not been paired with the presentation of food.

Child Behavior↗
PubMed1989

Effects of experience on the modification of food acceptance patterns.

Parallels have been drawn between persons at the two extremes of the life span: the very young and the very old. Some of these purported similarities, including referring to the latter portion of the life span as a "second childhood," are clearly unsupported by the data. The view presented above, however, suggests that experience with food continues to modify food acceptance patterns across the life span through associative conditioning. To the extent that the young and old have similar experiences with food, we can expect similar patterns of change in food acceptance to emerge. Research has been reviewed on the effects of experience on the development and modification of food acceptance patterns in children. Two aspects of this research--the associative conditioning of food cues to consequences and the effects of exposure on preference for novel foods--are particularly relevant to developing hypotheses regarding how experience with food could shape food acceptance patterns in the elderly. Research should be directed to exploring the social contexts and consequences of eating as possible contributors to reduced food acceptance among the elderly.

Aged↗
PubMed1987

What kind of exposure reduces children's food neophobia? Looking vs. tasting.

To determine the relative effectiveness of two different types of exposure on young children's preference for initially novel foods, 51 two- to five-year-old children received either "look" or "taste" exposures to seven novel fruits. Foods were exposed five, 10 or 15 times, and one food remained novel. Following the exposures, children made two judgments of each of the 21 pairs: one based on looking, the other on tasting the foods. Thurstone Case V scaling solutions were correlated with exposure frequency, and these were significant for the visual judgments of the looked at foods (r = 0.91), the visual judgments of the tasted (and looked at) foods (r = 0.97) and the taste judgments of the tasted foods (r = 0.94). The only non-significant relationship was for the taste judgments of the looked at (but never tasted) foods (r = 0.24). The results indicate that to obtain significant positive changes in preference, experience with the food must include experience in the modality that is relevant for the judgments. While visual experience produced enhanced visual preference judgments, visual experience was not sufficient to produce significantly enhanced taste preferences. This finding is consistent with a "learned safety" interpretation of the exposure effects noted in the taste judgments: experiences with novel tastes that are not followed by negative gastrointestinal consequences can produce enhanced taste preference.

Child, Preschool↗
PubMed1987

The role of experience in children's food acceptance patterns.

Results of studies conducted over the past ten years at the University of Illinois have shown that experience plays a major role in children's food acceptance patterns. Four aspects of experience with food and eating have been found to affect early food acceptance patterns: (1) the frequency of exposure to food; (2) associative conditioning of food cues to physiological consequences of eating; (3) associative conditioning of food cues to social context of feeding; and (4) learning more about which cues--physiological,environmental, cognitive--are relevant in the initiation, maintenance, and termination of eating. In addition, the quality of the social context of feeding has been shown to affect food acceptance and the extent to which children are attuned to cues of hunger and satiety in self-regulating food intake.

Attitude↗
PubMed1986

Caloric compensation and sensory specific satiety: evidence for self regulation of food intake by young children.

Twenty-one two and half- to five-year-old children and 26 25- to 35-year-old adults participated in an experiment designed to provide evidence for two behavioral mechanisms involved in self regulation of food intake: caloric compensation and sensory specific satiety. All participants were seen in two lunch sessions that differed in the caloric density of the preload presented. To obtain evidence on sensory specific satiety, preference data were obtained immediately before and after, and 20 min after preload consumption. Subjects then ate an ad libitum lunch and consumption was recorded. Both children's and adults' preferences for the food eaten declined relative to foods not eaten, providing the first evidence of sensory specific satiety in children. The patterns of preference did not differ with the caloric density of the food eaten. Children showed much clearer evidence for caloric compensation than did the adults.

Adult↗
PubMed1984

Time of day influences food acceptability.

To determine whether a food's acceptability changes with time of day and degree to which a food is appropriate for a given mealtime, preferences were obtained both in the morning and the afternoon for a set of foods which included items appropriate "for breakfast", "for dinner", or for either mealtime. A second purpose of the study was to determine whether such cultural rules regarding food appropriateness had been acquired by preschool children and whether the pattern of shifting acceptability with time of day predicted for adult subjects would also appear in the preference data of the children. Participants included 25 adults and 30 three- and four-year-old children. All subjects were seen twice, once in the morning and once in the late afternoon for two identical sessions. Half of the subjects in each age group were seen first in the morning, half were seen first in the afternoon. In these sessions food preferences for the set of foods varying in mealtime appropriateness were assessed and the foods were categorized as "for breakfast" of "for dinner". The preference data of both the adults and the children showed significant preference shifts with time of day, with breakfast items more preferred in the morning than the afternoon and dinner items more preferred in the morning than the afternoon. These shifts were larger for adults than for children but not significantly so.

Adult↗