Human beings are susceptible to sustained weight gain in the modern environment. Although both men and women can get fat, they get fat in different ways, and suffer different consequences. We review differences between men and women in the incidence of obesity, fat deposition patterns, fat metabolism, and the health consequences of obesity, and examine potential evolutionary explanations for these differences. Women generally have a larger proportion of body mass as fat, and are more likely to deposit fat subcutaneously and on their lower extremities; men are more likely to deposit fat in the abdominal region. Excess adipose tissue in the abdominal region, especially visceral fat, is associated with more health risks. Women have higher rates of reuptake of NEFA into adipose tissue; however, they also have higher rates of fat oxidation during prolonged exercise. Oestrogen appears to underlie many of these differences. Women bear higher nutrient costs during reproduction. Fat and fertility are linked in women, through leptin. Low leptin levels reduce fertility. Ovarian function of adult women is associated with their fatness at birth. In our evolutionary past food insecurity was a frequent occurrence. Women would have benefited from an increased ability to store fat in easily metabolisable depots. We suggest that the pattern of central obesity, more commonly seen in men, is not adaptive, but rather reflects the genetic drift hypothesis of human susceptibility to obesity. Female obesity, with excess adiposity in the lower extremities, reflects an exaggeration of an adaptation for female reproductive success. There is a growing worldwide epidemic of obesity. It affects men and women, young and old. For example, under the current US military's recommended enlistment standard for BMI (defined as weight in kilograms divided by the square of height in meters) 40 % of young women and 25 % of young men in the USA are not eligible due to being overweight (1) . Women of reproductive age have been especially susceptible. In 1999-2002, 62 % of US women aged 20 years or older were overweight (defined as having a BMI . 25 kg/m 2 ) and one-third were obese (BMI $ 30 kg/m 2 ) (2,3) . Obesity in adolescence also is an increasing concern; 15 % of girls aged 12 -19 years were overweight (defined as having a BMI $ the 95th percentile for age according to the Centers for Disease Control growth charts) (2) . What is amazing, and frightening, is how quickly this change in human body weight is occurring. Within a few generations the bell-curve of human-weight distribution has shifted and become skewed toward greater weight. The median-weight individual of today would have been considered to be heavier than average only a short time ago and there are more extremely obese individuals. This trend would appear to be continuing (2) . The rapidity with which the incidence of obesity has increased worldwide suggests that genetic change on a population level is an unlikely cause, although assortative mating, the increased probability that indivi...

This article's aim is to review the literature on racial and ethnic disparities in breastfeeding rates and practices, address barriers to breastfeeding among minority women, conduct a systematic review of breastfeeding interventions, and provide obstetrician-gynecologists with recommendations on how they can help increase rates among minority women. In order to do so, the literature of racial and ethnic disparities in breastfeeding rates and barriers among minority women was reviewed, and a systematic review of breastfeeding interventions among minority women on PubMed and MEDLINE was conducted. Racial and ethnic minority women continue to have lower breastfeeding rates than white women and are not close to meeting the Healthy People 2020 goals. Minority women report many barriers to breastfeeding. Major efforts are still needed to improve breastfeeding initiation and duration rates among minority women in the United States. Obstetrician-gynecologists have a unique opportunity to promote and support breastfeeding through their clinical practices and public policy, and their efforts can have a meaningful impact on the future health of the mother and child.

Lactation represents the greatest postnatal energetic expenditure for mammalian mothers, and a mother's ability to sustain the costs of lactation is influenced by her physical condition. Mothers in good condition may produce infants who weigh more, grow faster, and are more likely to survive than the infants of mothers in poor condition. These effects may be partially mediated through the quantity and quality of milk that mothers produce during lactation. However, we know relatively little about the relationships between maternal condition, milk composition, milk yield, and infant outcomes. Here, we present the first systematic investigation of the magnitude, sources, and consequences of individual variation in milk for an Old World monkey. Rhesus macaques produce dilute milk typical of the primate order, but there was substantial variation among mothers in the composition and amount of milk they produced and thus in the milk energy available to infants. Relative milk yield value (MYV), the grams of milk obtained by mammary evacuation after 3.5-4 h of maternal-infant separation, increased with maternal parity and was positively associated with infant weight. Both milk gross energy (GE) and MYV increased during lactation as infants aged. There was, however, a trade-off; those mothers with greater increases in GE had smaller increases in MYV, and their infants grew more slowly. These results from a well-fed captive population demonstrate that differences between mothers can have important implications for milk synthesis and infant outcome.Keywords milk composition and yield; parity; infant growth; maternal effects; life history For mammalian females, lactation is the most costly form of parental investment. Mothers vary in their ability to meet the costs of lactation, and maternal effects on infant outcomes are common among mammals. As such, maternal influences on infant phenotype contribute to the variation on which natural selection acts (Mosseau and Fox, 1998;Räsänen and Kruuk, 2007). In nonhuman primates, infant growth and survival have been linked to variation in maternal weight, parity, age, and social rank as well as the timing of birth (in Chlorocebus aethiops; age and weight Fairbanks and McGuire, 1995; in Papio sp maternal age; Cheney et al., 2004; rank and parity;Altmann and Alberts, 2005; in Macaca mulatta maternal age and adiposity; Johnson and Kapsalis, 1995; birth-timing, Drickamer, 1974; Fairbanks, 1996 andMaestripieri, 2009). It is likely that these maternal effects are at least partially mediated through the quantity or quality of milk that mothers provide their infants during lactation, but currently little is known about interindividual differences in milk synthesis.To develop a full understanding of parent-offspring conflict and life-history theory in primates, it is important to identify the sources, magnitude, and consequences of variation in milk composition and output (Trivers, 1974;Bowman and Lee, 1995;Johnson and Kapsalis, 1995;Lee, 1996;Johnson, 2003). Although variation in...

Anticipatory physiological regulation is an adaptive strategy that enables animals to respond faster to physiologic and metabolic challenges. The cephalic phase responses are anticipatory responses that prepare animals to digest, absorb and metabolize nutrients. They enable the sensory aspects of the food to interact with the metabolic state of the animal to influence feeding behavior. The anticipatory digestive secretions and metabolic adjustments in response to food cues are key adaptations that affect digestive and metabolic efficiency and aid in controlling the resulting elevation of metabolic fuels in the blood. Cephalic phase responses enable digestion, metabolism and appetite to be regulated in a coordinated fashion. These responses have significant effects on meal size. For example, if the cephalic phase insulin response is blocked the result is poor glucose control and smaller meals. Cephalic phase responses also are linked to motivation to feed, and may play a more direct role in regulating meal size beyond the permissive one of ameliorating negative consequences of feeding. For example, the orexigenic peptide ghrelin appears to display a cephalic phase response, rising before expected meal times. This anticipatory ghrelin response increases appetite; interestingly it also enhances fat absorption, linking appetite with digestion and metabolism.

The relative lack of associations between maternal diet or body composition and milk composition at Cebu is consistent with past studies and suggests that milk composition may be buffered against fluctuations in maternal dietary intake or nutritional status. We speculate that the tendency for milk composition to vary between populations faced with different nutritional ecologies, but to show minimal responsiveness to intake during lactation, may enhance the reliability of milk composition as a stable intergenerational cue of typical local environmental quality.

Free oligosaccharides are abundant components of mammalian milk and have primary roles as prebiotic compounds, in immune defense, and in brain development. Mass spectrometry-based technique is applied to profile milk oligosaccharides from apes (chimpanzee, gorilla, and siamang), new world monkeys (golden lion tamarin and common marmoset), and an old world monkey (rhesus). The purpose of this study was to evaluate the patterns of primate milk oligosaccharide composition from a phylogenetic perspective in order to assess the extent to which the compositions of hMOs derives from ancestral, primate patterns as opposed to more recent evolutionary events. Milk oligosaccharides were quantitated by nanoflow liquid chromatography on chip-based devices. The relative abundances of fucosylated and sialylated milk oligosaccharides in primates were also determined. For a systematic and comprehensive study of evolutionary patterns of milk oligosaccharides, cluster analysis of primate milk was performed using the chromatographic profile. In general, the oligosaccharides in primate milk, including humans, are more complex and exhibit greater diversity compared to the ones in non-primate milk. A detailed comparison of the oligosaccharides across evolution revealed non-sequential developmental pattern, i.e. that primate milk oligosaccharides do not necessarily cluster according to the primate phylogeny. This report represents the first comprehensive and quantitative effort to profile and elucidate the structures of free milk oligosaccharides so that they can be related to glycan function in different primates.

Chronic variable prenatal stress or maternal high-fat diet results in offspring that are significantly heavier by the end of the first postnatal week with increased adiposity by weaning. It is unclear, however, what role maternal care and diet play in the ontogenesis of this phenotype and what contributions come from differences already established in the rat pups. In the present studies, we examined maternal behavior and milk composition as well as offspring ingestive behavior. Our aim was to better understand the development of the obese phenotype in offspring from dams subjected to prenatal stress and/or fed a high-fat (HF) diet during gestation and lactation. We found that dams maintained on a HF diet through gestation and lactation spent significantly more time nursing their pups during the first postnatal week. In addition, offspring of prenatal stress dams consumed more milk at postnatal day (PND) 3 and offspring of HF dams consume more milk on PND 7 in an independent ingestion test. Milk from HF dams showed a significant increase in fat content from PND 10-21. Together these results suggest that gestational dietary or stress manipulations can alter the rat offspring's developmental environment, evidence of which is apparent by PND 3. Alterations in maternal care, milk composition, and pup consumption during the early postnatal period may contribute to long-term changes in body weight and adiposity induced by maternal prenatal stress or high-fat diet.

This report explores aspects of developing obesity in two captive populations of common marmosets (Callithrix jacchus), a small primate with a short lifespan that may be of value in modeling chronic aspects of obesity acquisition and its lifetime effects. Two populations were examined. In study 1, body composition, lipid parameters, and glucose metabolic parameters were measured in a population of 64 adult animals. Animals classified as obese (>80th percentile relative fat based on sex) displayed both dyslipidemia (higher triglyceride and very low–density lipoprotein (VLDL)) and altered glucose metabolism (higher fasting glucose and HbA1c). Using operational definitions of atypical values for factors associated with metabolic syndrome in humans, five subjects (7.8%) had at least three atypical factors and five others had two atypical factors. A previously unreported finding in these normally sexually monomorphic primates was higher body weight, fat weights, and percent fat in females compared to males. In a second study, longitudinal weight data for a larger population (n = 210) were analyzed to evaluate the development of high weight animals. Differences in weights for animals that would exceed the 90th percentile in early adulthood were evident from infancy, with a 15% difference in weight between future-large weight vs. their future-normal weight litter mates as early as 4–6 months of age. The marmoset, therefore, demonstrates similar suites of obesity-related alterations to those seen in other primates, including humans, suggesting that this species is worthy of consideration for obesity studies in which its fast maturity, high fertility, relatively short lifespan, and small size may be of advantage.