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K M Rasmussen

Publications and source records attributed to K M Rasmussen.

At least 19 recordsLinked to original sources
PubMed2005

The nutritional phenotype in the age of metabolomics.

The concept of the nutritional phenotype is proposed as a defined and integrated set of genetic, proteomic, metabolomic, functional, and behavioral factors that, when measured, form the basis for assessment of human nutritional status. The nutritional phenotype integrates the effects of diet on disease/wellness and is the quantitative indication of the paths by which genes and environment exert their effects on health. Advances in technology and in fundamental biological knowledge make it possible to define and measure the nutritional phenotype accurately in a cross section of individuals with various states of health and disease. This growing base of data and knowledge could serve as a resource for all scientific disciplines involved in human health. Nutritional sciences should be a prime mover in making key decisions that include: what environmental inputs (in addition to diet) are needed; what genes/proteins/metabolites should be measured; what end-point phenotypes should be included; and what informatics tools are available to ask nutritionally relevant questions. Nutrition should be the major discipline establishing how the elements of the nutritional phenotype vary as a function of diet. Nutritional sciences should also be instrumental in linking the elements that are responsive to diet with the functional outcomes in organisms that derive from them. As the first step in this initiative, a prioritized list of genomic, proteomic, and metabolomic as well as functional and behavioral measures that defines a practically useful subset of the nutritional phenotype for use in clinical and epidemiological investigations must be developed. From this list, analytic platforms must then be identified that are capable of delivering highly quantitative data on these endpoints. This conceptualization of a nutritional phenotype provides a concrete form and substance to the recognized future of nutritional sciences as a field addressing diet, integrated metabolism, and health.

Diet↗
PubMed2004

Metabolomics in the opening decade of the 21st century: building the roads to individualized health.

It is rapidly becoming possible to measure hundreds or thousands of metabolites in small samples of biological fluids or tissues. This makes it possible to assess the metabolic component of nutritional phenotypes and will allow individualized dietary recommendations. ASNS has to take action to ensure that appropriate technologies are developed and that metabolic databases are constructed with the right inputs and organization. The relations between diet and metabolomic profiles and between those profiles and health and disease must be established. ASNS also should consider the social implications of these advances and plan for their appropriate utilization.

Animals↗
PubMed2003

Associations between reproduction and maternal body weight: examining the component parts of a full reproductive cycle.

OBJECTIVE: Many transitional societies currently face both extremes of nutritional status, undernutrition and overnutrition. Women of reproductive age are at high risk of these conditions. The purpose of this review is to consider evidence for relationships between reproduction and nutritional status in women from societies of varying economic development, using body weight or weight-for-height as indicators of maternal nutritional status. DESIGN: The conceptual framework guiding this review is that the duration of the reproductive cycle varies as a function of its component parts, which include (i) pregnancy, (ii) lactation, (iii) the non-pregnant/non-lactating (NP/NL) interval or, possibly, (iv) an overlap between lactation and next pregnancy. All component parts of the complete cycle vary in length and are associated with changes in nutritional status. A variety of factors ('proximal and distal determinants') influence the duration of the component parts of the reproductive cycle. This framework is used to examine current knowledge of changes in maternal nutritional status during each of these parts. RESULTS: Women in affluent societies retain some weight with each pregnancy, beyond that of non-pregnant women. Women in less affluent societies retain less weight with each pregnancy. During lactation, women in both affluent and less affluent societies experience only modest weight loss. During the NP/NL interval, women in affluent societies tend to gain weight, whereas weight of women in less affluent societies is likely to fluctuate. CONCLUSIONS: We conclude that there is a dearth of information on certain parts of the cycle, particularly the periods of overlap of lactation with pregnancy and the NP/NL interval.

Adult↗
PubMed2001

A low-fat diet but not food restriction improves lactational performance in obese rats.

Rats fed a high-fat diet before and during lactation have difficulty initiating lactation and have high pup mortality rates, low milk production and, consequently, poor pup growth. To determine if these adverse outcomes can be mitigated with dietary changes made after delivery, obese Sprague-Dawley rats (who had previously been fed a high-fat diet [AIN-93M, modified to contain 35% fat, w/w]) were assigned at parturition to continue to be fed this diet (HF) or switched to free access to a corresponding low-fat (LF) diet (AIN-93M, 4% fat w/w) or switched to the LF diet and restricted to consuming only 75% of ad libitum intake (LF/R). Dams lost weight during lactation, but weight loss was much less in the LF group (19g) than in the other two groups (47 and 59g, HF and LF/R, respectively). There was no appreciable change in body water; body fat decreased by about half in all groups, but most substantially in the LF/R group. Compared with the HF group, milk production was 50% higher in the LF group and 12% lower in the LF/R group. Milk lipid concentration tended to be higher and milk water concentration lower in the HF compared with the other two groups. Growth of the litters of the LF dams was significantly higher than both HF and LF/R dams. These results indicate that switching to a low-fat diet mitigates the negative effects of obesity and continued high-fat feeding on lactational performance and pup growth. Consumption of restricted quantities of a low-fat diet negatively affected milk production and failed to improve pup growth, despite the dams' mobilization of body fat in support of lactation.

Animals↗
PubMed2001

Obesity may impair lactogenesis II.

Data from livestock species and experimental animal models suggest that excess body fatness may impair lactogenesis. For example, it has long been known that overfed dairy cows are at risk of fat cow syndrome, a condition characterized by lactation failure in the early postpartum period. Obese rats often lose their litters in the early postpartum period to primary lactation failure. A negative association between high body mass index (BMI) before conception and the duration of lactation has been documented in studies from diverse human populations. Findings from our laboratory establish that among women who ever attempted to breastfeed their infants, high BMI before conception was also associated with failure to initiate breastfeeding successfully. In a more recent study, we found that high prepregnant BMI was specifically associated with later onset of lactogenesis II. This was mediated by parity but not by breastfeeding behavior. Psychosocial factors related to a woman's intention to breastfeed and her planned duration of breastfeeding did not modify this association. Taken together, these findings in animals and women strongly suggest that maternal obesity in the perinatal period is a cause of delayed lactogenesis.

Animals↗
PubMed2001

The "fetal origins" hypothesis: challenges and opportunities for maternal and child nutrition.

The "fetal origins" hypothesis postulates that conditions, most likely nutritional, "program" the fetus for the development of chronic diseases in adulthood. Associations between the newborn's size at birth and various determinants or consequences of chronic diseases have been identified in many, but not all, of the available studies. It remains to be established whether these associations are causal. Remarkably little information is available on the specific role of maternal nutritional status. The role of birth weight remains difficult to interpret except as a proxy for events in intrauterine life. Unfortunately, birth weight does not make an important contribution to the population attributable risk of cardiovascular disease; lifestyle factors during adulthood make much greater contributions. Data from experimental species suggest possible mechanisms for the origin of chronic disease early in life. It is too soon to use this research as a basis for new interventions directed at pregnant women for the purpose of reducing chronic disease in their offspring.

Birth Weight↗
PubMed1999

Impact of lactation on maternal body weight and body composition.

Women worldwide generally lose weight and body fat during lactation. This loss, although increased by longer, more intensive breastfeeding, is modest and may be reduced by increased food intake and decreased activity. Higher parity and older age are associated with greater weight loss postpartum among poorly nourished women. Well-nourished women or those who breastfeed only for a limited time may not return to their prepregnant weight or body composition by the end of the lactation period. Those who are overweight or obese may have difficulty initiating or maintaining lactation. For the majority of women in the world, lactation is unlikely to represent a threat to their health. To advise women on how to optimize their health and lactational performance, one must consider all of the changes in maternal nutritional status that occur during a reproductive cycle, which may or may not compensate for the modest decreases in body weight associated with lactation.

Body Composition↗
PubMed1998

Recognizing the reversible nature of child-feeding decisions: breastfeeding, weaning, and relactation patterns in a shanty town community of Lima, Peru.

Researchers have normally considered weaning to be a non-reversible event. To determine the validity of this assumption, we interviewed 36 mothers of toddlers who were living in a poor shanty town of Lima, Peru. Data from 32 women were complete and used in this analysis. Mothers described their beliefs, practices, and decisions about breastfeeding, weaning, and relactation (the reintroduction of breastfeeding after weaning). We recorded attempted weaning events if the mother reported (1) purposefully not breastfeeding with the intention to wean, or (2) carrying out an action that was believed to cause the child to stop breastfeeding. Using a constant comparative approach, references to child-feeding decisions were coded, categorized, and analyzed. All mothers breastfed for at least 12 months; the median duration of breastfeeding was 25 months. There were several different patterns of child-feeding. Thirteen women never attempted to wean their children or had weaned on the first attempt. The majority (n = 19) of women, however, attempted to wean their children - some as early as 3 months of age but relactated between less than 1 day and 3 months later. Factors that influenced feeding decisions were primarily related to maternal and child health, and maternal time commitments. Children were weaned when there was a perceived problem of maternal health or time commitments and child health was not at risk of deterioration. Mothers postponed weaning because of poor child health. The primary reason for relactation was a child's negative reaction to weaning (e.g., incessant crying or refusal to eat). Personalities of the mother and child were important determinants of feeding decisions. These results demonstrate that maternal and child factors jointly influence child-feeding decisions and that these decisions are easily reversed. As relactation is culturally acceptable, health practitioners should consider recommending relactation when children have been prematurely weaned and human milk would improve their nutritional and health status.

Adult↗
PubMed1998

Linking maternal and infant benefits of a nutritional supplement during pregnancy and lactation.

To evaluate the effect of a nutritional supplement on change in women's weight during a reproductive cycle and on the difference in birth weight between one infant and the previous one, we analyzed data on 176 complete reproductive cycles from an experiment that was conducted in rural Guatemala. Women with an initial weight <50 kg were classified as marginally nourished or malnourished. Women whose intake of the supplement was in the top 2 tertiles were distinguished from those whose intake was in the lowest tertile. Linear regression modeling was used to estimate the effect of supplementation on these outcomes and to control for confounding factors. Malnourished women gained weight during the reproductive cycle, but their second (study) infant tended to weigh less at birth than their prior-born infant. Higher intakes of supplement were associated with a less negative difference in birth weight. Marginally nourished women lost weight during the reproductive cycle and their second (study) infant tended to weigh more at birth than their prior-born infant. Higher intakes of supplement were associated with a less negative weight [corrected] trend for the women themselves. Well-nourished women and their infants did not show any of these benefits from supplementation. These findings help explain past contradictory findings on maternal depletion as well as on the benefits of nutritional supplementation for mothers and their infants.

Adult↗
PubMed1998

Impact of food supplementation during lactation on infant breast-milk intake and on the proportion of infants exclusively breast-fed.

To evaluate whether milk production can be improved by increasing food intake, a randomized, double-blind, supplementation trial was completed among 102 lactating Guatemalan women. The subjects were undernourished, as indicated by their low values for calf circumference (CC) and the small size of their infants at birth. A high-energy (2.14 MJ/d, HES) and a low-energy (0.50 MJ/d, LES) supplement were distributed 6 d/wk from wk 5 to 25 of lactation. Data were evaluated using repeated-measures analysis of variance on the increments from initial values for each outcome variable with one-tailed tests of statistical significance. The maternal energy intake increased 1.18 MJ/d (P < 0.01) more among the HES than the LES women. Benefit from supplementation was more evident among the more undernourished (CC </= median value, 29.5 cm) women. Among these 53 lower-CC women, infant milk and milk energy intakes were 10% higher (64 g/d and 14 MJ/d, respectively, at wk 25) in the HES than the LES group. After controlling for other determinants of infant milk and energy intakes in regression analyses, the significance of these differences increased to P < 0.04. However, there was no detectable effect on infant growth. Logistic regression analysis was used to show that HES women were significantly (P < 0.05) more likely than LES women to be exclusively breast-feeding their infants at wk 20, the time when the effect of supplementation was most evident. These findings establish that milk production and the duration of exclusive breast-feeding of undernourished women can be improved with the provision of supplemental food.

Adult↗
PubMed1998

Effects of under- and overnutrition on lactation in laboratory rats.

To study the effects of maternal nutritional status on lactational performance, the diets of laboratory rats were manipulated with food restriction or increases in fat concentration. Compared with rats fed control diets ad libitum, conception rate, milk production and litter growth decreased and milk fat concentration increased in both chronically food restricted and obese animals. Chronically food restricted rats mobilized body fat and reduced their energy expenditure for maintenance and activity. Differences in suckling pattern between control and food-restricted rats affected hormone concentrations important for successful lactation. Obese rats experienced greater difficulty than controls in delivering their pups and more of their pups died in the first days of life. Milk production among obese rats may be constrained by poor appetite and the high heat production that characterizes lactation in litter-bearing species. There are many parallels as well as important differences between results obtained from these models and findings in nursing women. Nevertheless, these models provide useful information about the possible mechanisms by which maternal nutritional status affects lactational performance.

Animals↗
PubMed1997

Duration of breastfeeding associated with obesity during adolescence.

The relationship between duration of breastfeeding and obesity (body mass index > or = 85 percentile) at adolescence was investigated in a white, rural population (n = 136) in which confounding by race was absent and confounding by socioeconomic status was expected to be minimal. Relevant data were abstracted from hospital charts. When examined independently, minimal (< or = 2 months) or no breastfeeding was positively associated with adolescent obesity (p < 0.03). This association was present in the lower but not the higher socioeconomic status group. However, when sex, birthweight, and socioeconomic status were included in a multiple regression model, duration of breastfeeding was no longer significantly associated with obesity during adolescence.

Adolescent↗
PubMed1997

Breast milk or animal-product foods improve linear growth of Peruvian toddlers consuming marginal diets.

Although breast-feeding is widely accepted as important for infant health, its benefits during the second year of life have been questioned. We analyzed data from 107 breast-fed and weaned Peruvian children living in a periurban community to determine whether breast milk contributed to improved linear growth between 12 and 15 mo of age. Breast-feeding frequency was self-reported; intakes of complementary foods and animal products were estimated from a food-frequency survey. Multivariate-linear-regression analysis was used to predict the length of the children at 15 mo of age. Determinants of length included length and weight-for-length at 12 mo of age (US National Center for Health Statistics standards), interval between 12- and 15-mo measurements, breast-feeding frequency, incidence of diarrhea, and intakes of complementary and animal-product foods. Complementary foods, animal-product foods, and breast milk all promoted toddlers' linear growth. In subjects with low intakes of animal-product foods, breast-feeding was positively associated (P < 0.05) with linear growth. There was a 0.5-cm/3 mo difference in linear growth between weaned toddlers and children who consumed the average number of feedings of breast milk. Linear growth was also positively associated with intake of animal-product foods in children with low intakes of complementary foods. The negative association between diarrhea and linear growth did not occur in subjects with high complementary-food intakes. When the family's diet is low in quality, breast milk is an especially important source of energy, protein, and accompanying micronutrients in young children. Thus, continued breast-feeding after 1 y of age, in conjunction with feeding of complementary foods, should be encouraged in toddlers living in poor circumstances.

Animals↗
PubMed1997

Maternal obesity and breast-feeding success in a rural population of white women.

Maternal obesity interferes with the initiation and maintenance of lactation in animal models but it has not been investigated widely in women. We reviewed medical records from a white population to examine the relation between prepregnant overweight [body mass index (BMI; in kg/m2) 26.1-29.0] and obesity (BMI > 29.0) on initiation and duration of breast-feeding. Logistic regression revealed that of those who ever put their infants to the breast (n = 810), women who were overweight [odds ratio (OR) = 2.54, P < 0.05] or obese (OR = 3.65, P < 0.0008) had less success initiating breast-feeding than did their normal-weight counterparts (BMI < 26.1). Proportional-hazards regression revealed higher rates of discontinuation of exclusive breast-feeding in overweight (RR = 1.42, P < 0.04) and obese (RR = 1.43, P < 0.02) women and higher discontinuation of breast-feeding to any extent in overweight (RR = 1.68, P < 0.006) and obese (RR = 1.73, P = 0.001) women. Controlling for parity, socioeconomic status, maternal education, and other factors that often covary with maternal obesity and breast-feeding did not change these results. These results suggest that excessive fatness in the reproductive period may inhibit lactational performance in women.

Adult↗
PubMed1997

Association of breastfeeding and stunting in Peruvian toddlers: an example of reverse causality.

BACKGROUND: Child feeding recommendations include breastfeeding beyond 12 months, however, some researchers have reported increased rates of malnutrition in breastfed toddlers. A negative association between growth and breast-feeding may reflect reverse causality; that is, the outcome (growth) is a determinant of the predictor (breastfeeding), and not vice versa. We examined this question with data from 134 Peruvian toddlers. METHODS: A linear regression analysis predicted length at the age of 15 months by length at 12 months, study interval, and 12-14.9-month breastfeeding, complementary food intake, and diarrhoeal incidence. This analysis defined the association between breastfeeding and linear growth. To elucidate the direction of the effect between breastfeeding and linear growth, logistic regression was used to predict the probability of weaning by the end of 14 months. Determinants included weight-for-age (W/A) at 12 months, complementary food intake at 9-11.9 months, and change in diarrhoeal incidence between 9 and 14.9 months. RESULTS: There was a significant (P < 0.01) interaction of breastfeeding, diarrhoeal incidence, and complementary food intake on length at 15 months. Increased breastfeeding was associated with a 1.0 cm decrease in length gain when dietary intake was low and diarrhoeal morbidity was high, implying that breastfeeding is harmful. The logistic analysis, however, demonstrated that the risk of weaning decreased only when W/A and dietary intake were low and diarrhoeal morbidity was high. CONCLUSIONS: The negative association between breastfeeding and linear growth reflected reverse causality. Increased breastfeeding did not lead to poor growth; children's poor growth and health led to increased breastfeeding. Children's health must be considered when evaluating the association of breastfeeding with anthropometric outcomes.

Anthropometry↗
PubMed1997

Consumption of a high fat diet impairs reproductive performance in Sprague-Dawley rats.

Rats made obese by cafeteria feeding have poor reproductive outcomes. To investigate this phenomenon in animals fed a more nutritionally adequate diet, female rats were fed either a high fat (HF) (modified AIN-76A, 35 g fat/100 g diet) or a control (C) (AIN-76A, 5 g fat/100 g diet), diet, beginning at 27 d of age. To assess reproductive performance, rats were studied at d 0, 5 and 18 of pregnancy and on d 3 of lactation. Pregnancy rates were significantly (P < 0.001) lower in the high fat-fed rats than in the control-fed rats (56.4 and 89.1%, respectively). There was no difference between groups in total pregnancy weight gain or the proportion of weight gained during pregnancy that was retained by the dam. High fat-fed dams tended to gain weight more rapidly early in gestation than control-fed dams and then less rapidly than control-fed dams during the last week of gestation. Litter number and pup weight at birth did not differ between groups, but of high fat-fed pups had significantly higher (P < 0.04) mortality rates than pups of control-fed dams (16.5 and 7.7%, respectively) over the first 3 d of life. Control-fed dams experienced the expected reduction (P < 0.05) in plasma insulin concentrations between the end of pregnancy and early lactation, but high fat-fed dams did not. Thus, physiological mechanisms controlling distribution of metabolic fuels may not be functioning properly in high fat-fed dams. Therefore, consuming a high fat diet reduces a rat's capacity to conceive and ability to maintain her litter during the perinatal period.

Animals↗
PubMed1997

Food supplementation during lactation shortens anestrus and elevates gonadotropins in rats.

Breastfeeding delays the resumption of ovulation in women, a phenomenon particularly important in less developed areas. Although human and animal studies indicate that undernutrition extends the period of lactational anestrus, the effect of improving nutritional status during lactation on this time of infecundability, however, is less clear. To assess the effects of food supplementation on duration of lactational anestrus, Sprague-Dawley rats were assigned to one of three dietary groups: 1) control (C), given unrestricted access to diet AIN-76A; 2) food-restricted (FR), fed 50% of the control intake; and 3) food-supplemented (FS), food-restricted until d 0 of lactation and thereafter given unrestricted access to diet AIN-76A. Time to first detectable proestrus was monitored starting on d 10 of lactation. Nursing behaviors and gonadotropin and prolactin concentrations were measured in both intact and ovariectomized dams on d 10, 15 and 20 of lactation; we report these data only on the ovariectomized group, which represents the more appropriate animal model of human reproductive physiology during lactation. Proestrus returned significantly (P < 0.0001) sooner in both FS (18.1 +/- 2.4 d) and C (18.0 +/- 2.9 d) than in FR (28.8 +/- 2.8 d) intact dams. FS rats had higher luteinizing hormone and follicle stimulating hormone concentrations than FR rats (P < 0.0001 for each). Prolactin concentrations were lower on d 20 than on d 10 of lactation for all groups (P < 0.02), but we found no effect of dietary treatment. FS rats spent more time away from their pups (P < 0.05) and experienced less suckling (P < 0.05) than FR rats on d 15 of lactation. These results indicate that food supplementation of previously underfed rats hastens the return of ovulation and is accompanied by alterations in nursing behaviors.

Anestrus↗