Days Of Food Intake Research Articles

Diet Quality of Frequent Fast-Food Consumers on a Non-Fast Food Intake Day Is Similar to a Day with Fast Food, What We Eat in America, NHANES 2013-2016

BackgroundFrequent fast food (FF) consumers may make more healthful food choices at eating occasions without FF. However, it is not clear if poor diet quality of frequent FF consumers is a function of FF consumption or less healthful food choices overall. ObjectiveThe objective of this study was to compare diet quality, energy, and nutrient intakes of infrequent FF consumers (INFREQ) with that of frequent FF consumers on an intake day with FF (FREQ-FF) or without FF (FREQ_NO FF). DesignThis study is a cross-sectional analysis of 1 day dietary intake data from What We Eat in America, National Health and Nutrition Examination Survey 2013-2016, the dietary intake component of National Health and Nutrition Examination Survey. Participants/settingParticipants included adults aged 20 years and older (N = 4,012), who, during the previous 7 days, reported no consumption of FF or pizza (n = 2,142 INFREQ) or reported FF or pizza three or more times and either had FF/pizza (n = 1,455 FREQ_FF) or did not have FF/pizza (n = 415 FREQ_NO FF) on the intake day. Main outcome measuresMain outcomes were energy, nutrient density (nutrient intake per 1,000 kcal), and diet quality evaluated using Healthy Eating Index (HEI) 2015. Statistical analyses performedGroup comparisons were made using t tests. Differences were considered significant at P < 0.001. ResultsCompared with INFREQ consumers, FREQ_FF consumers had higher intakes of energy and fat per 1,000 kcal, lower scores for total HEI and most components, and lower nutrient densities of most micronutrients (P < 0.001). HEI component scores of INFREQ consumers for vegetables, fruit, whole grains, and added sugars were higher than FREQ_FF consumers (P < 0.001). Energy intake, most nutrient densities, and total HEI and component scores of FREQ_NO FF consumers were not significantly different from FREQ_FF consumers with the exception of fruit but were different from INFREQ consumers for some nutrients and HEI components. ConclusionsResults suggest diet quality and nutrient intake of frequent FF consumers on a non-FF intake day is not markedly different from a day with FF.

Feeding Level and Frequency Effects in Captive Nile Tilapia (Oreochromis niloticus) Fry

Hence, the interest in variations in feeding frequencies in captive Nile tilapia fry. Two hundred forty mixed-sex fries, intended to test the feeding frequency, with an initial average weight of 0.03 0.04g; corresponding to an average size of 1.4 cm, randomly distributed in (12) boxes each containing 4 fry/L. Fry are fed with Naturalleva import pellets for 30 days. A single photoperiod is studied for long days (18L: 6D) and to maintain an intensity of 2500 lux. The Statistics data are analyzed using software (R) and tested for normality and homogeneity of variance before being subjected to variance analysis (ANOVA; p≤0.05) and Duncan’s method. A multiple range test was used to compare the mean differences. A feed frequency of 4 times and six (06) times a day shows more efficient use of food than once, twice, and three times a day of food intake. The overall growth parameters for larval tilapia rearing are satisfactory, with the feeding regime set at 35% of the biomass of captive residents for two weeks of rearing, and 17.5% for the remaining two weeks. These results represent standards for the launch of captive breeding of the Nile tilapia strain, which will allow freeing themselves from the often expensive and foreign currency imports of fry for the country.

FASTING TECHNIQUES – CHANGING THE WAY, YOU LOOK AT THERAPY

At present, various complications such as diabetes, cardiovascular diseases, cancer, and neurological disorders have become treatable, almost completely, but the drugs used for the treatment may cause some severe side effects such as hypoglycemia, kidney complications, diarrhea, anemia, rashes, dyskinesia, insomnia, hypotension, confusion, hallucinations, compulsive behavior, and neurological complications. Some treatments cause defects in whole organ systems including damage to the immune system, lungs, heart, nerve endings, and reproductive organs. Many treatment approaches are using non-pharmacological techniques for treating diseases, without synthetic drugs. One such technique is fasting, a process where starvation conditions are imitated voluntarily. Intermittent fasting is done in ratios of fasting and food intake, where a person deprives himself of food for 16 h and food intake is followed for the rest of 8 h. Alternate day fasting includes alternate days of food intake and fasting. Time-restricted feeding is done by allowing food consumption only during the metabolically active phase of the day. Fasting mimicking diet is done by reducing food intake to very small levels which mimics the conditions of fasting. Reported beneficial effects of fasting have been found in diseases such as cancer, blood pressure disorders, autoimmune diseases, fibrosis, inflammation, insulin sensitivity, and oxidative stress.

Inter-goal conflict and facilitation as predictors of adherence to dieting goals: an ecological momentary assessment study

Objectives: To examine dieting goals within a system of individual goals, and the patterns by personally-relevant goals might interfere or facilitate each other.Design: 94 dieters completed an assessment of goals using Little’s personal project analysis. Participants identified 7 goals; one of which was pre-defined as adhering to diet. Over the beginning 14 days of their diet, participants completed an Ecological Momentary Assessment study recording their food intake in real-time. Every evening, participants reported their goal engagement and which goals conflicted or facilitated with each other.Main outcome measures/results: Over the study duration, 1452 days of food intake and goal conflict/facilitation were recorded. Participants completed an average of 1.54 (SD = 0.85) snacks, an average of 0.94 (SD = 1.81) goal conflicts, and 4.16 (SD = 4.70) goal facilitations per day. Inter-goal conflict was associated with a significant but small improvement on individuals’ mood, but was not associated with daily dietary intake or long-term weight-loss. Similarly, inter-goal facilitation was not associated with daily dietary intake or long-term weight-loss. Daily food intake was a significant predictor of long-term weight-loss.Conclusions: The results of this study suggest the impact of inter-goal conflict and facilitation on dieting is not via overall snack or food consumption.

Validity of the Remote Food Photography Method Against Doubly Labeled Water Among Minority Preschoolers.

ObjectiveTo determine the validity of energy intake (EI) estimations made using the Remote Food Photography Method (RFPM) compared to the doubly-labeled water (DLW) method in minority preschool children in a free-living environment.MethodsSeven days of food intake and spot urine samples excluding first void collections for DLW analysis were obtained on 39 3-to-5 year old Hispanic and African American children. Using an iPhone, caregivers captured before and after pictures of the child’s intake and pictures were wirelessly transmitted to trained raters who estimated portion size using existing visual estimation procedures and energy and macronutrients were calculated. Paired t-test, mean differences and Bland-Altman limits of agreement were performed.ResultsThe mean EI using the RFPM was 1,191 ± 256 kcal/d and 1,412 ± 220 kcal/d by the DLW method, resulting in a mean underestimate of 222 kcal/d (−15.6%) (p<0.0001) that was consistent regardless of intake. The RFPM underestimated EI by −28.5% in 34 children and overestimated EI by 15.6% in 5 children.ConclusionsThe RFPM underestimated total EI when compared to the DLW method among preschoolers. Further refinement of the RFPM is needed for assessing EI of young children.

Performance of statistical methods to correct food intake distribution: comparison between observed and estimated usual intake.

There are statistical methods that remove the within-person random error and estimate the usual intake when there is a second 24-h recall (24HR) for at least a subsample of the study population. We aimed to compare the distribution of usual food intake estimated by statistical models with the distribution of observed usual intake. A total of 302 individuals from Rio de Janeiro (Brazil) answered twenty, non-consecutive 24HR; the average length of follow-up was 3 months. The usual food intake was considered as the average of the 20 collection days of food intake. Using data sets with a pair of 2 collection days, usual percentiles of intake of the selected foods using two methods were estimated (National Cancer Institute (NCI) method and Multiple Source Method (MSM)). These estimates were compared with the percentiles of the observed usual intake. Selected foods comprised a range of parameter distributions: skewness, percentage of zero intakes and within- and between-person intakes. Both methods performed well but failed in some situations. In most cases, NCI and MSM produced similar percentiles between each other and values very close to the true intake, and they better represented the usual intake compared with 2-d mean. The smallest precision was observed in the upper tail of the distribution. In spite of the underestimation and overestimation of percentiles of intake, from a public health standpoint, these biases appear not to be of major concern.

Eating at the right time of day

aily cycles of light and dark due to the rotation ofthe earth around its axis have dictated how life hasevolved on Earth. Organisms have thus developedthe ability to predict these 24-h cycles by developing anendogenous circadian clock, which is entrained to externalcues. In mammals, circadian rhythms are controlled andgeneratedbythecentralormastercircadianclocklocatedinthe suprachiasmatic nuclei (SCN)of the anterior hypothala-mus in the brain [1]. This master clock consists of multiplesingle-cellcircadianoscillatorsthataresynchronizedto24hby environmental factors, primarily dark/light and alsotemperature and food. The retina perceives the dark/lightcycleinformationandtransmitsthissignaltotheSCNviatheretinohypothalamic tract. The SCN then transmits theseinputs to peripheral oscillators located outside the SCN.Such peripheral oscillators exist in nearly all peripheraltissues such as liver, adipose, pancreas, muscle and blood.Therefore, circadian rhythms have been described for vir-tually all physiological and biochemical processes, includ-ing behavioural ones [2].The SCN may influence the cardiovascular systemprimarily through multisynaptic neural projections to theheart,adrenalcortex,kidneysandvasculatureandresultantneural or endocrine effects, and secondarily by circadianinfluences on behaviours such as sleep and activity andfeeding patterns [3]. Thus, the master SCN clock sendsperiodic signals to the peripheral oscillators in order toprevent dampening of circadian rhythms, but a complexreciprocal relationship seems also to exist. Indeed, alteredbehaviours, for example when sleeping or food intake isdesynchronized from normal circadian patterns, seem toaffect the peripheral oscillators or clocks in particular,resulting in metabolic processes that are decoupled fromthe primarily light-driven SCN [4,5]. In addition, the multi-plicityofperipheralclocksinthehumanorganismhasbeenfound to comprise networks that both control circadianprocessesandaretightlyconnectedtometabolicandneuralcontrol networks, such that disturbance of one affects theother. Hence, misalignment of circadian rhythms in theSCN and peripheral tissues may constitute an importantunderling factor for a variety of metabolic and vasculardisorders such as obesity, metabolic syndrome, diabetesand hypertension [4,6,7]. Adverse cardiometabolic end-points including higher glucose, insulin, leptin, ghrelin,glucagon-like peptide-1, cortisol, blood pressure (BP)and catecholamines have been reported as results ofmisalignments invoked by food intake/irregular meal fre-quency (for comprehensive reviews see, for instance[1,2,4]). This new evidence illustrates how knowledge onchronobiology, that is the circadian influences on mech-anisms involved in metabolic and cardiovascular disease,and their interaction with behavioural influences, may beimportant for optimizing preventive lifestyle measures orpharmacological therapy [8,9]. For instance, preventingadversebehaviouraltriggersatspecificvulnerablecircadiantimes [4] or prescribing ingestion of medicines at specifictimes in anticipation of vulnerable periods [9,10] maymaximize their beneficial effects. Currently, such timedmeasures or chronotherapy constitute new avenues ofresearchforthepreventionandtreatmentofmanydiseases,including asthma, arthritis, cancer and seasonal affectivedisorder [11].Chronotherapy has been recommended for the treat-ment of major cardiovascular risk factors such as hyperten-sion [11] and dyslipidaemia [10], though typically in thecontext of pharmacotherapy. Timing of meals may con-stitute one such lifestyle therapeutical tool as well. In fact,some form of dietary chronotherapy is already imple-mented in metabolic diseases such as diabetes, whereinthe timing of meals is particularly important, as patientsneed to coordinate insulin administration with calorieintake. Interestingly, in recognition of the chronobiologicalaspects of nutrition, Franz Halberg [12] called for researchon the ‘when to eat’ question more than two decades ago.Currently, the beneficial chronobiological effects of foodintake (e.g. meal time, frequency and regularity) are beingsubject of intensive research as a potential additional or

Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males

IntroductionThe daily number of meals has an effect on postprandial glucose and insulin responses, which may affect substrate partitioning and thus weight control. This study investigated the effects of meal frequency on 24 h profiles of metabolic markers and substrate partitioning.MethodsTwelve (BMI:21.6±0.6 kg/m2) healthy male subjects stayed after 3 days of food intake and physical activity standardization 2×36 hours in a respiration chamber to measure substrate partitioning. All subjects randomly received two isoenergetic diets with a Low meal Frequency (3×; LFr) or a High meal Frequency (14×; HFr) consisting of 15 En% protein, 30 En% fat, and 55 En% carbohydrates. Blood was sampled at fixed time points during the day to measure metabolic markers and satiety hormones.ResultsGlucose and insulin profiles showed greater fluctuations, but a lower AUC of glucose in the LFr diet compared with the HFr diet. No differences between the frequency diets were observed on fat and carbohydrate oxidation. Though, protein oxidation and RMR (in this case SMR + DIT) were significantly increased in the LFr diet compared with the HFr diet. The LFr diet increased satiety and reduced hunger ratings compared with the HFr diet during the day.ConclusionThe higher rise and subsequently fall of insulin in the LFr diet did not lead to a higher fat oxidation as hypothesized. The LFr diet decreased glucose levels throughout the day (AUC) indicating glycemic improvements. RMR and appetite control increased in the LFr diet, which can be relevant for body weight control on the long term.Trial RegistrationClinicalTrails.gov NCT01034293

Validity of physical activity and food consumption questionnaire for children aged seven to ten years old

OBJECTIVES: assess reproducibility and concurrent validity of the questionnaire focusing on a typical physical activity and food intake day (DAFA) to measure physical activity and food intake in children between seven and ten years old. METHODS: sixty nine children recruited in a public school located in Florianópolis, Santa Catarina participated of the survey. Reproducibility was determined by comparing measures of two DAFA applications in a two week interval while concurrent validity of physical activity was assessed by comparing DAFA with a questionnaire filled by parents/teachers. As for food intake, the reference method was a 24 hour recordatory. Analysis included concordance coefficient determination, intraclass correlation, adjusted kappa coefficient and Wilcoxon and Kruskal-Wallis tests. RESULTS: concordance coefficient was of 88% (school commuting) and 68% (physical activity related attitude) while intraclass correlation was of 0.85 for the general measure for physical activity. Using the report of parents/teachers, the children were broken into three groups of physical activities (low/medium/high), it should be considered that DAFA scores differed significantly. As for food intake measuring, 80% of concordance was determined between DAFA applications. Interinstrument convergence was substantial/moderate in relation to 17 food items. CONCLUSIONS: DAFA allows for physical activity and food intake measures in children with good reproducibility and moderate validation evidence.

The Time of Day of Food Intake Influences Overall Intake in Humans

Circadian and diurnal rhythms affect food intake, and earlier research has suggested that meal sizes increase, whereas the after-meal intervals and satiety ratios decrease over the day. We hypothesized that the time of day of food intake would be related to total intake such that intake early in the day would tend to reduce overall intake, whereas intake later in the day would tend to increase intake over the entire day. The intakes of 375 male and 492 female free-living individuals, previously obtained via 7-d diet diaries, were reanalyzed. The total and meal intakes of food energy, the amounts of the macronutrients ingested and the density of intake occurring during five 4-h periods (0600-0959, 1000-1359, 1400-1759, 1800-2159 and 2200-0159 h) were identified and related to overall and meal intakes during the entire day. The proportion of intake in the morning was negatively correlated with overall intake (r=-0.13, P<0.01), whereas the proportion ingested late in the evening was positively correlated with overall intake (r=0.14, P<0.01). The energy densities of intake during all periods of the day were positively related to overall intake (range, r=0.13-0.23, P<0.01). The results suggest that low energy density intake during any portion of the day can reduce overall intake, that intake in the morning is particularly satiating and can reduce the total amount ingested for the day, and that intake in the late night lacks satiating value and can result in greater overall daily intake.

Relationships between Vitamin and Mineral Supplement use, Dietary Intake, and Dietary Adequacy among Adolescents

Objective To examine patterns of supplement use among US adolescents and the relationship between supplement use and dietary intake and adequacy. Design Adolescents self-reported 2 days of food intake using the 24-hour recall method and supplement use during a personal interview conducted as part of the 1994 Continuing Survey of Food Intakes of Individuals (CSFII). Subjects A national sample of 423 adolescents included in the 1994 CSFII survey. Statistical analysis χ 2 analysis was used to determine which demographic factors were significantly related to patterns of supplement use. Weighted percentages of adolescents by category of supplement use for selected vitamins and minerals (calcium; iron; zinc; folic acid; and vitamins A, B-6, C, and E) are presented. Relationships between dietary intake of macronutrients and vitamins and minerals among adolescents and supplement use were determined using a least-squares model of general linear regression. Results Approximately one-third of adolescents reported using supplements, with 15.6% of youth using them on a daily basis. The majority of supplement users reported taking multivitamins (N=95; 65.5%) whereas only one-third of supplement users reported taking individual vitamins or minerals. Supplement use was found to vary by gender, household size, and US region of residence. Adolescents who reported using supplements had higher mean dietary intakes of most micronutrients and lower intakes of total and saturated fat than those who did not use supplements. More than one-third of adolescents had dietary intakes of vitamins A and E, calcium, and zinc that were <75% of the US Recommended Dietary Allowance. Applications/Conclusions The majority of US adolescents do not use vitamin or mineral supplements. Interestingly, adolescents who do use supplements, even on an infrequent basis, consume diets that are more nutrient-dense than those who do not use supplements. Dietary intakes of several micronutrients were inadequate among all adolescents in this study, regardless of supplement use status. There is a need to develop and implement programs aimed at improving the dietary intakes of US adolescents. J Am Diet Assoc. 2000;100:905–910.

Prevalence of Amenorrhea in High School and Collegiate Cross-Country Runners

Drinkwater has found that women who always had regular menstrual cycles have higher lumbar densities. Since there is little published data on menstrual status of athletes, 72 female cross-country runners were evaluated from three teams in Michigan. A questionnaire, consisting of 15 questions, which had previously been tested for reliability was completed by the subjects. This identified past and current menstrual history and exercise pattern. Nutritional analysis using Nutritionist IV was completed. Three usual days of food intake were recorded by collegiate athletes. Results indicated that of the high school runners (age 14–17 years), a total of 59% responded they were either amenorrheic (AM) or oligomenorrheic (OL). Of this group, 54% (n=15) have had either a stress fracture or shin splints. The greatest number, 61% (n=17) consumed 2–4 cups of milk/day, whereas 21% (n=6), consumed ≤ cup milk/day. Only 3% consumed a calcium supplement. Analysis of collegiate data (n=44) (ages 18–22 years) revealed 19, and 33% were AM or OL, respectively. Evaluation indicated 50% were within acceptable body mass intake range. The mean miles ran per week was 31–40. There was low caloric intake and x of 1805±655 kcals; only 50% met carbohydrate recommendations. Mean fat and calcium intakes were 26 gm and 296 mg respectively. AM may result in low bone density at multiple skeletal sites. Optimal nutrition is vital to performance and the well-being of the female athlete.

The Phenomenon of “Picky Eater”: A Behavioral Marker in Eating Patterns of Toddlers

Objective: To determine if toddlers who were considered “picky eaters” had lower dietary scores than non-picky eaters, and if family environment and socioeconomic status were significantly related to picky eater status and dietary scores.Methods: An incomplete block design provided two interviews at randomly assigned times (24, 28, 32, or 36 months) of Caucasian mothers from upper socioeconomic (n=74) and lower socioeconomic status (n=44). Using trained interviewers, 6 days of food intake, two administrations of a questionnaire about toddler’s eating behavior, and one administration of the Family Environment Scales were collected in the home. MANOVA, discriminant function analysis, and logistic regression procedures were used to determine significant differences between picky and non-picky eater groups.Results: Picky eaters had lower dietary variety (p=.03) and diversity scores (p=.009) than non-picky eaters. Mothers of picky eaters compared to those of non-picky eaters used persuasion (p=.0001) and ranked their child’s eating behaviors as more problematic (p=.0001).Conclusion: Toddlers perceived by their mothers as picky eaters had significantly lower dietary variety and diversity scores. Parents need information and strategies to increase the number of foods acceptable to their toddlers and to develop a sound feeding plan.

Nutrient Intakes of Senior Women: Balancing the Low-Fat Message

Nutrient intakes based on six days of food intake were collected from 52 elderly Nova Scotian women. Mean reported energy intake was 1600 kilocalories, of which fat contributed 31%. Mean intakes of zinc and Vitamin D were below recommendations. Other nutrients of concern were protein, calcium, folate, and vitamins B6 and B12. Nutrition education efforts should be directed at assisting older people to maintain the generally recommended low fat intake, while stressing the desirability of a balanced food intake of sufficient quantity, which includes low-fat milk and dairy products, lean meats and legumes as sources of nutrients in low supply.

Fruit and Vegetable intake among Service Members Eating in Government Operated Dining Facilities

LEARNING OUTCOME: To examine daily fruit and vegetable consumption of over 5,072 observed days of food intake by service members subsisting in government operated institutional feeding programs.Previous surveys of the US population, the 1976-1980 National Health and Nutrition Examination Survey (NHANES II) and the 1989 to 1991 Continuing Surveys of Food Intakes by Individuals (CSFII) both have indicated that typical intakes of fruits and vegetables are substantially below recommended levels. Using data from nine dietary studies, we examined service members who subsist in government run feeding programs to determine how they differ from the general population comparing similar age groupings (20-39 years). Military dietary assessments were conducted by collectors trained in visual estimation of portion sizes (actually observing each food tray) which improves validity of food selection characterization compared to self-reported data collected in NHANES II and CSFII studies. The findings of this retrospective investigation showed an estimated 45% of male (n=3,847 intake days) and 36% of female (n=1,225 intake days) service members met the Dietary Guidelines for Americans recommendation of 2 daily servings of fruit and 3 servings of vegetables as compared to only 10.3% of males (n=1,503) and 5.8% of females (n=2,042) in the CSFII, and 8% of males (n=1,360) and 5% of females (n=1,462) in NHANES II which represents the nonsinstitutionalized US population. Supporting documentation distinguishing between dark green and deep yellow vegetables; cruciferous vegetables, and citrus fruit and vegetable intake were made. Ninety-two percent of military members had a rich source of vitamin C on any given day as opposed to only 23 percent of the general population. These results suggest a need to develop strategies for all Americans to overcome barriers to eating fruits and vegetables, particularly cruciferous vegetables and fruits and vegetables rich in carotenoids.

Nutrient Intake of Nursing‐Home Residents Receiving Pureed Foods or a Regular Diet

To evaluate (1) the nutrient content of menus planned for regular consistency meals and pureed meals in a long-term care facility and (2) to assess nutrient intakes of women consuming these meals. A descriptive survey. A nursing home facility in central Pennsylvania. Fifty-one female nursing home residents were chosen randomly. Thirty-one received a regular diet and 20 received a pureed diet. Demographic and health variables were collected from medical records. Nutrient variables were calculated for regular and pureed consistency meals, as served. Nutrient intake data for each woman were based on seven consecutive days of food intake and nutrient supplement use. Energy and nutrient values for regular diet menus (i.e., food served) were higher than for pureed menus, but both had values exceeding recommended allowances for most nutrients. Average energy and nutrient intakes were similar for both groups of women (t test, P < 0.05). Data showed that many women in both groups had lower than the recommended intakes of iron, zinc, calcium, and Vitamin D. Both regular and pureed consistency diets provided to residents met current recommended allowances. Diet consistency did not affect nutrient intakes. Intakes were adequate overall; however, a low intake of the same nutrients generally occurred in both groups.

The validity of the 24 hour recall for estimating the energy and selected nutrient intakes of a group of rural Malawian preschool children

The validity of the 24‐hour recall (24 HR) for estimating group aggregate and individual daily energy, protein, calcium, iron, zinc and vitamin C intakes of 29 rural Malawian children (4–6 years) was assessed by comparing weighed record (WR) and 24 HR dietary data collected for the same day of food intake. There were no significant differences comparing group median energy and nutrient intakes estimated using the two techniques. The percentage differences between group mean intakes ranged from 1% (vitamin C) to 16% (Ca). In general, these differences were reduced when morning meal intakes were omitted to eliminate the systematic bias affecting estimates of porridge intake. Spearmans and intra‐class correlation coefficients ranged from 0.28 (vitamic C) to 0.55 (Zn), and from 0.14 (vitamin C) to 0.51 (Zn), respectively. Less than 35% of the nutrient intakes estimated using the 24 HR were within ± 10% of those estimated via the WR (range = 12% for vitamin C and Ca to 33% for protein), and over 50% of the sub...

Food deprivation and ingestion induce reciprocal changes in neuropeptide Y concentrations in the paraventricular nucleus

We have studied the effects on neuropeptide Y (NPY) concentration in six hypothalamic nuclei, viz. medial preoptic area (MPOA), paraventricular nucleus (PVN), median eminence (ME), arcuate nucleus (ARC), ventromedial nucleus (VMN) and dorsomedial nucleus (DMN) of food deprivation (FD) for 2, 3, or 4 days or FD for 4 days followed by one day ad lib food intake (FI) in male rats. Hypothalamic nuclei were microdissected by the technique of Palkovits and processed for measurement of NPY immunoreactivity by RIA. NPY-like immunoreactivity in the ME, VMN and DMN was unaffected by FD or FI, but the remaining three nuclei—the ARC, MPOA and PVN—displayed a different pattern of changes in NPY levels in response to either FD or FD followed by FI. In the ARC, NPY levels rose significantly at day 3 and 4 after FD and remained elevated even after one day of FI. In the MPOA, while FD for 4 days had no effect, NPY concentration increased significantly in response to FI. In contrast, in the PVN, a site implicated in the control of feeding behavior, the NPY response to FD and FI was markedly different. FD elicited a gradual, time-related increase in NPY levels to reach highest concentration on day 4 and thereafter, following one day of FI, NPY levels fell dramatically to the range found in control satiated rats. These results show that (1) NPY levels display site-specific changes in response to FD and FI; (2) a dramatic reciprocal change in the PVN NPY levels occurred in response to disturbances in the daily food intake as produced by sequential FD and FI; (3) other hypothalamic sites, such as the ARC and MPOA, displayed only unidirectional increments in response to FD and FI. The observation of site-specific changes in the PVN NPY levels further support the hypothesis that NPY may be a physiological neurochemical signal in the PVN that normally evokes feeding in the rat.

Number of Days of Food Intake Records Required to Estimate Individual and Group Nutrient Intakes with Defined Confidence

The number of days of food intake data needed to estimate the intake of 29 male (n = 13) and female (n = 16) adult subjects, individually and as a group, was determined for food energy and 18 nutrients. The food intake records were collected in a year-long study conducted by the U.S. Department of Agriculture’s Beltsville Human Nutrition Research Center. Each individual’s average intake of nutrients and standard deviation over the year were assumed to reflect his or her “usual” intake and day-to-day variability. Confidence intervals (P < 0.05) for each individual’s usual intake were constructed, and from these the number of days of dietary records needed for estimated individual and group intake to be within 10% of usual intake was calculated. The results indicated that the number of days of food intake records needed to predict the usual nutrient intake of an individual varied substantially among individuals for the same nutrient and within individuals for different nutrients; e.g., food energy required the fewest days (averaging 31) and vitamin A the most (averaging 433). This was considerably higher than the number of days needed to estimate mean nutrient intake for this group, which ranged from 3 for food energy to 41 for vitamin A. Fewer days would be needed for larger groups.