Individual Weight Gain Research Articles

Interaction between genes involved in energy intake regulation and diet in obesity.

Obesity is a multifactorial, complex, and public health problem worldwide. Interaction between genes and environment as associated with diet may predispose an individual to obesity. In this sense, nutrigenetics appears to be a strategy that can improve understanding of the gene-diet interaction. The aim of this literature review was to summarize data from studies of genes involved in the regulation of energy intake (melanocortin 4 receptor [MC4R], fat mass and obesity-associated [FTO], ghrelin [GHRL], leptin [LEP], and cholecystokinin [CCK]) and diet interaction in obesity. The presence of polymorphisms in MC4R, FTO, leptin, and the respective receptor appear to be associated with higher energy and total lipid consumption. Polymorphisms in FTO, leptin, and leptin receptor are also related to increased intake of saturated fatty acids. Individuals with the MC4R, FTO, and ghrelin polymorphisms, who submitted themselves for weight loss intervention, appeared to achieve weight loss similar to individuals without polymorphisms in these genes. Additionally, protein seems to interact with these genes, which increases or decreases appetite, or to drive or lessen body weight recovery. Additionally, polymorphisms in these genes were found to be associated with inappropriate eating behaviors, such as increased consumption of sweets and snacks, consumption of large food portions, desire to eat, and eating associated with emotional issues. Preliminary data has supported the gene-diet interaction in determining weight loss and gain in individuals with polymorphisms in the genes involved in energy intake. Despite the advent of nutrigenetics in obesity, it is still too early to define the dietary management for weight loss based on the presence or absence of obesity polymorphisms.

Effect of Single Dose of Antimicrobial Administration at Birth on Fecal Microbiota Development and Prevalence of Antimicrobial Resistance Genes in Piglets.

Optimization of antimicrobial use in swine management systems requires full understanding of antimicrobial-induced changes on the developmental dynamics of gut microbiota and the prevalence of antimicrobial resistance genes (ARGs). The purpose of this study was to evaluate the impacts of early life antimicrobial intervention on fecal microbiota development, and prevalence of selected ARGs (ermB, tetO, tetW, tetC, sulI, sulII, and blaCTX–M) in neonatal piglets. A total of 48 litters were randomly allocated into one of six treatment groups soon after birth. Treatments were as follows: control (CONT), ceftiofur crystalline free acid (CCFA), ceftiofur hydrochloride (CHC), oxytetracycline (OTC), procaine penicillin G (PPG), and tulathromycin (TUL). Fecal swabs were collected from piglets at days 0 (prior to treatment), 5, 10, 15, and 20 post treatment. Sequencing analysis of the V3-V4 hypervariable region of the 16S rRNA gene and selected ARGs were performed using the Illumina Miseq platform. Our results showed that, while early life antimicrobial prophylaxis had no effect on individual weight gain, or mortality, it was associated with minor shifts in the composition of fecal microbiota and noticeable changes in the abundance of selected ARGs. Unifrac distance metrics revealed that the microbial communities of the piglets that received different treatments (CCFA, CHC, OTC, PPG, and TUL) did not cluster distinctly from CONT piglets. Compared to CONT group, PPG-treated piglets exhibited a significant increase in the relative abundance of ermB and tetW at day 20 of life. Tulathromycin treatment also resulted in a significant increase in the abundance of tetW at days 10 and 20, and ermB at day 20. Collectively, these results demonstrate that the shifts in fecal microbiota structure caused by perinatal antimicrobial intervention are modest and limited to particular groups of microbial taxa. However, early life PPG and TUL intervention could promote the selection of ARGs in herds. While additional investigations are required to explore the consistency of these findings across larger populations, these results could open the door to new perspectives on the utility of early life antimicrobial administration to healthy neonates in swine management systems.

Administration of host‐derived probiotics does not affect utilization of soybean meal enriched diets in juvenile turbot (Scophthalmus maximus)

In today's aquaculture, the cost-intensive and scarce fishmeal is increasingly replaced by plant-based feedstuff such as soybean meal (SBM). However, SBM contains saponins which can have adverse effects on fish's digestive tract potentially culminating in severe enteritis. In a 60 day feeding trial we studied the use of autochthonous bacteria as probiotics upon SBM supplementation on juvenile turbot. Growth performance, feed conversion, body composition and health status were assessed for five different treatment groups, comprising a fishmeal control (FM ctrl), a SBM control without probiotics (SBM ctrl) and three multi-species probiotic treatments. For the production of the probiotic treatments a basal diet with a composition identical to the SBM ctrl including 40% SBM of total dry matter likewise was prepared. The basal diet was stepwise top coated with three different probiotic supplementations: (a) three distinct isolates with saponin-metabolizing ability (SBM + degrad); (b) three distinct isolates inhibitory towards the pathogen, Tenacibaculum maritimum (SBM + anta); and (c) a commercial probiotic application (SBM + com). Individual weight gain was highest in FM ctrl but only SBM + degrad diet showed a significantly lower value (p < 0.05). The feed conversion ratio was lowest in FM ctrl and significantly higher in SBM + degrad (p < 0.01). The protein retention efficiency did only differ significantly between FM ctrl and SBM + degrad (p < 0.05), whereas lipid retention efficiency remained unaffected. Whole body composition and gross energy content were similar in all treatments lacking significant differences. The condition factor was significantly elevated in SBM + degrad compared to FM ctrl (p < 0.05). Hematocrit was highest in FM ctrl and significantly lower in the other treatments (p < 0.01) with SBM + com accounting for the lowest value (p < 0.001). The hepatosomatic index was slightly increased in FM ctrl but no significant difference was detected. Regarding the spleen somatic index SBM + anta treatment revealed the highest and SBM ctrl a significantly lower value (p < 0.05). In conclusion, the growth performance of fish did not benefit from the different probiotic treatments, while body composition and gross energy content remained at an appropriate level. Moreover, the overall health status was on a sufficient level in all treatments which confirms the high dietary tolerability of our putative probiotic isolates by the fish.

Cabotegravir Is Not Associated With Weight Gain in Human Immunodeficiency Virus-uninfected Individuals in HPTN 077.

Studies in human immunodeficiency virus (HIV)-infected individuals suggest excess weight gain with integrase inhibitor-based antiretroviral therapy. The HIV Prevention Trials Network Study 077 evaluated changes in weight and fasting metabolic parameters in HIV-uninfected individuals randomized to cabotegravir or a placebo. No differences between arms were found for change in weight or fasting metabolic parameters overall or for subgroups.

Evaluating the most suitable nonlinear growth model for turbot (Scophthalmus maximus) in aquaculture 2 (weight application): Multi‐criteria model selection and growth prediction

Seeking the most suitable model to describe the growth of turbot, we analysed growth data of two different turbot (Scophthalmus maximus) strains reared communally in a recirculating aquaculture system. We fitted 10 different nonlinear growth models to individual weight gain data (n = 2,010) during the grow-out phase. Analyses were carried out for each strain, for sexes within strains and for a pooled data set containing both strains and sexes. To assess the model performance, three different criteria are used. Further, a growth-simulation was performed to evaluate the shape of the generated curve. This way we could assess the capability of the models to predict future growth. The 3-parametric Gompertz model achieved the best fit in 42.9% of all cases tested and the lowest Bayesian information criterion in 100% of cases. The model produced realistically shaped curves and asymptotic values matching the biological attributes of the species. In contrast, 5-parametric functions projected unrealistically shaped curves and predicted improbable mature sizes. Our results show that increasing number of parameters do not lead to increasing goodness of fit, but tend to result in overfitting, and demonstrate the advantages of the 3-parametric Gompertz model for describing the growth of turbot.

Effect of stocking density on growth and survival of the prawn Macrobrachium tenellum, cultured in a recirculating aquaculture system

The stocking density of the freshwater prawn native to the Mexican Pacific coast, Macrobrachium tenellum , has not been evaluated in a recirculating aquaculture system. M. tenellum prawns with an average wet weight of 1.71 ± 0.11 g were reared for 60 days at three stocking densities (T1 = 10 ind m -2 ; T2 = 15 ind m -2 ; T3 = 20 ind -2 ), in nine (1 m 2 ) tanks connected to a recirculating aquaculture system inside a greenhouse. Average individual weight gain (AIWG), biomass weight gain (BWG), specific growth rate (SGR), food conversion ratio (FCR) and survival rate (SR) were determined. Stocking density affected the BWG and SR. The lowest BWG was observed at the highest density (T1, 20.70 ± 4.75 g m -2 ; T2, 20.75 ± 4.72 g m -2 ; T3, 11.31 ± 3.65 g m -2 ), although weight per area unit increased with densities. SR decreased with increasing density (T1, 77.77 ± 9.62%; T2, 59.25 ± 12.83%; T3, 44.44 ± 4.81%). Other parameters did not show a difference between densities, with a maximum average individual weight at T2 (5.41 ± 1.14 g). The overall results suggested that stocking density affected the productivity and survival but not the individual growth of juvenile M. tenellum prawns cultured in a recirculating aquaculture system.

Effects of Modest Weight Gain On Circulating Free Fatty Acids

BackgroundIncreases in circulating free‐fatty acids (FFAs) contribute to obesity‐associated cardiometabolic pathology and may be considered a surrogate marker for adipose tissue dysfunction. However, alterations in FFA metabolism resulting from modest weight gain have not been previously evaluated.ObjectiveExamine the changes in FFAs during modest weight gain in healthy individuals and to investigate the relationship between regional fat depots.Study DesignWe evaluated the effects of overfeeding in 8 healthy, non‐obese participants (4 men; age 29 ± 5.7 years; BMI: 25.1 ± 2.1 kg/m2). FFA concentrations were measured using liquid chromatography/mass spectrometry under fasting conditions and during oral‐glucose tolerance test (OGTT) at baseline and after 8 weeks of weight gain. Prior to the baseline and weight gain visits, subjects consumed isocaloric macro‐nutrient stable diet for three days (50% carbohydrate, 35% fat and 15% protein). Body composition and regional fat depots were assessed using dual‐energy X‐ray absorptiometry and abdominal computed tomography scans.ResultsOverfeeding was accompanied by 3.9 ± 1.6 kg weight gain (p=0.01) resulting from 2.9 ± 0.9 kg (p=0.01) increase in fat mass and 1.0 ± 0.9 kg (p=0.04) increase in fat‐free mass. Compared to baseline, fasting FFA (439 ± 162 μM vs. 368 ± 123 μM, p=0.55) and area under the curve (AUC) for FFA during OGTT (23319 ± 11686 μM. min−1 vs. 20495 ± 4847 μM.min−1, p=0.55) did not change with weight gain. However, at 120 min. of the OGTT FFA were significantly greater after weight gain (60 ± 18 μM vs. 77 ± 34 μM, p=0.04). We found a negative relationship between relative changes in visceral fat area and FFA at 120 min of glucose challenge (rho=−0.76, p=0.03). Furthermore, relative changes in fasting FFA and AUC for FFA during OGTT with weight gain were associated with baseline total fat mass (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.81; p=0.02) and baseline abdominal fat area (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.79; p=0.02).ConclusionsModest weight gain does not alter fasting FFA or overall FFA response to oral glucose challenge. However, our data suggest development of early stages of adipose tissue insulin resistance which is apparent via lesser suppression of FFA at 120 min. of OGTT. Furthermore, the relationships between fasting FFA, AUC‐FFA, and baseline fat mass suggest that individuals with high baseline adiposity may be more susceptible to develop adipose tissue insulin resistance with weight gain.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Excess early postnatal weight gain and blood pressure in healthy young children

Blood pressure (BP) tracks from childhood to adulthood, and early BP trajectories predict cardiovascular disease risk later in life. Excess postnatal weight gain is associated with vascular changes early in life. However, to what extent it is associated with children's BP is largely unknown. In 853 healthy 5-year-old children of the Wheezing-Illnesses-Study-Leidsche-Rijn (WHISTLER) birth cohort, systolic (SBP) and diastolic BP (DBP) were measured, and z scores of individual weight gain rates adjusted for length gain rates were calculated using at least two weight and length measurements from birth until 3 months of age. Linear regression analyses were conducted to investigate the association between weight gain rates adjusted for length gain rates and BP adjusted for sex and ethnicity. Each standard deviation increase in weight gain rates adjusted for length gain rates was associated with 0.9 mmHg (95% CI 0.3, 1.5) higher sitting SBP after adjustment for confounders. Particularly in children in the lowest birth size decile, high excess weight gain was associated with higher sitting SBP values compared to children with low weight gain rates adjusted for length gain rates. BMI and visceral adipose tissue partly explained the association between excess weight gain and sitting SBP (β 0.5 mmHg, 95% CI -0.3, 1.3). Weight gain rates adjusted for length gain rates were not associated with supine SBP or DBP. Children with excess weight gain, properly adjusted for length gain, in the first three months of life, particularly those with a small birth size, showed higher sitting systolic BP at the age of 5 years.

The Effect of Light-Emitting Diode Light on the Physical Traits of Chicks

Environmental conditions including light are considered a critical element of chicks well-being. The aim of the present study was to investigate the effect of LED light on the physical traits of chicks. We took forty-one-day-old chicks and randomly separated it into two groups. The chicks in the first group were reared under the effect of incandescent lamp light and in the second one were under the effect of white LED lighting. Chicks were daily monitored for individual chick body, weight gain, feed intake, feather color and fear responses. The distance between chicks and source of light was 50 cm. Student’s t-test test was used for statistical evaluation at p < 0.05 level. The results of the current study showed that chicks reared under incandescent light bulb had significantly higher body weight compared with chicks reared under LED light. The magnitude of body weight in LED group was lower (1192.75 ± 149.9 g) compared to incandescent light group (1307.75 ± 110.5 g). The obtained results revealed that LED light reared chicks were more active; it showed long mobility duration and high levels of exploration in the farm as compared to those in incandescent light group. The results also indicated that incandescent light chicks were less fearful than LED chicks. Furthermore, the study showed that LED light reared chicks have pale pink combs and white feathers that cover all over the body. On the other hand, incandescent light reared chicks have dark red combs and whitish-yellow feathers that cover certain areas of the body especially chick wings, tail and head.

Effect of different weaning time on the growth and survival ofCommon carp (Cyprinus carpio L.) larvae

Within our experiment, we studied the combined effect of live food application and feed training on the production parameters of carp larvae. In addition, we examined whether there is a difference in the growth rate and survival rate of the specimens of Szeged mirror landrace reared in similar stocking density but with different treatments.&#x0D; Specimens of Szeged mirror landrace from induced propagation were placed into 12 pieces of 40-liter aquaria. For the 4 different treatments, (K, A3, A6, A9), live food (Artemia salina) was fed, as well as feed training was applied.&#x0D; We also sought to find an answer as to how our feeding and rearing conditions can affect the production parameters of common carp fries and what impact these conditions may have on their survival rates. At the end of the 2-week experiment we determined the individual weight gain of the carp fries, their survival rate and the biomass growth. The purpose of the study is to examine the optimum timing of shifting from live food to feed for carp larvae.

Changes in body composition and metabolic disease risk.

As individuals gain weight, they increase the amount of fat that they accrue on their body. This causes adipocytes to enlarge and increases not only subcutaneous fat but also deposits fat in other vulnerable areas of the body. This ectopic fat is deposited in the intra-abdominal visceral fat depot, in muscle, in the liver and in the beta cells. Fat in these locations initiates a dysfunctional state in these insulin-sensitive tissues leading to insulin resistance, the appearance of the Metabolic Syndrome, and an increased risk of developing both type 2 diabetes and cardiovascular disease. A loss of weight and with it a loss of fat decreases this risk.

Problematic eating behaviours, changes in appetite, and weight gain in Major Depressive Disorder: The role of leptin

BackgroundAppetite and weight changes are core symptoms of Major Depressive Disorder (MDD), and those with MDD are at increased risk of obesity, cardiovascular disease and metabolic disorders. Leptin promotes satiety, with leptin dysregulation and resistance noted in obesity. However, the role of leptin in weight changes in MDD is not established. This study investigates leptin levels in relation to appetite and weight changes and problematic eating behaviours in MDD. MethodsPlasma leptin levels, psychopathology and biometrics were compared between participants meeting DSM-5 diagnostic criteria for MDD (n = 63) and healthy controls (n = 60). Depressed participants were also sub-categorised according to increased, decreased or unchanged appetite and weight. The Dutch Eating Behaviour Questionnaire and Yale Food Addiction Scale were examined in a subset of participants with MDD. ResultsFemales with increased appetite/weight had higher leptin levels than those with stable or reduced appetite/weight, however males showed the opposite effect. Leptin levels were positively correlated with problematic eating behaviours. One quarter of the depressed subset, all females, met the Yale criteria for food addiction, approximately double the rates reported in general community samples. LimitationsThe study is limited by a cross sectional design and a small sample size in the subset analysis of eating behaviours. ConclusionsThe results provide new information about associations between leptin, sex-specific weight and appetite changes and problematic eating behaviours, which may be risk factors for cardiovascular and metabolic diseases in MDD, particularly in females. Future longitudinal research investigating leptin as a risk factor for weight gain in MDD is warranted, and may lead to early interventions aimed at preventing weight gain in at-risk individuals.

Variations Of Stocking Density And Type Of Feed For Growth And Survival Of Catfish (Clarias gariepinus)

The research aimed to analyze the interaction, variation of stocking densities and effect of different types of feed on growth and survival of catfish (Clarias gariepinus) seeds in the plastic ponds and their interaction. The research was carried out in West Kotawaringin, Pangkalan Bun of Central Kalimantan from May to July 2017. A completely randomized design with two-factor experiment (stocking density and types of feed) were applied in the study, namely 100 seeds/m3 (treatment A1), 150 seeds/m3 (treatment A2), 100 % commercial pellet (treatment B1), 100 % chicken intestine (treatment B2), and 50 % commercial pellet and 50 % chicken intestine (treatment B3). Catfish with initial body weight 1 g were reared in the plastic pond (1x1x1x1 m3) for 60 days. The results showed that individual weight gain was range 35,22 to 60,12 g, the best treatment A2B3. Survival rate ranged from 40,00 – 76,66%, the best treatment A1B2.

The relation of atypical antipsychotic use and stress with weight in individuals at clinical high risk for psychosis.

Atypical antipsychotics (AT) and stress are related to weight gain in individuals with severe mental illness. This cross-sectional study examines AT use, stressful life events, and baseline weight in a sample of youth at clinical high risk for psychosis. Results showed that dependent and desirable life events moderated the relationship between AT use and weight after controlling for demographic factors and selective serotonin reuptake inhibitor antidepressant (AD) use. The relation of AD and weight was explored as a secondary analysis and showed no relation between AD use and weight. Further, stress did not moderate the relationship between AD medication and weight after controlling for antipsychotic use. Results suggest that stress exposure may exacerbate the relationship between ATs and increased weight in clinical high-risk populations. Findings have implications for the development of interventions to address psychosocial factors that worsen or buffer the adverse effects of antipsychotic medication on weight.

Do environmental factors drive obesity? Evidence from international graduate students.

International students offer a unique window into the role environmental factors play in driving obesity. Naïve estimates of the relationship between environmental factors and obesity are often plagued by reverse causation, sample selection, and omitted variable bias. In this study, we survey international students at 40 public universities across the United States. We use this unique data to link the weight gain of international students to the prevalence of obesity where they live. We argue that our estimates are less likely to be biased as international students have limited control over the environment to which they are exposed upon arrival in the United States. We find that students living in areas with a higher prevalence of obesity show a biologically important and statistically significantly greater increase in weight as compared to those living in areas with a lower prevalence of obesity. Results provide cautious evidence that environmental characteristics of a region can affect the weight gain of individuals.

Trends and correlates of unhealthy dieting behaviours among adolescents in the United States, 1999\u20132013

BackgroundThe increase in adiposity problems among United States adolescents has been accompanied by persistently high prevalence of unhealthy dieting behaviours (UDBs) such as fasting, taking diet pills/powders/liquids, and vomiting/taking laxatives. This study aimed to examine the associations of self-perceptions of weight status, weight change intentions (WCIs) and UDBs with sex, age and race, as well as trends of UDBs in American adolescents across the weight spectrum.MethodsData come from the biennial cross-sectional, school-based surveys, the Youth Risk Behaviour Surveillance System (1999–2013, n = 113,542). The outcome measures were the self-reported UDBs: fasting for 24 h or more; taking diet pills/powders/liquids; and vomiting/taking laxatives. Sex-stratified logistic regressions assessed relationships between weight status misperceptions across all weight statuses, race and WCIs with UDBs. Differential trends between races were assessed using race*year interaction terms.ResultsIn males, all non-White races had higher odds of fasting and vomiting/taking laxatives than Whites (except fasting in Hispanic/Latinos), with Adjusted Odds Ratios (AORs) between 1.44 and 2.07. In females, Black/African Americans and Hispanic/Latinos had lower odds of taking diet pills/powders/liquids compared to Whites (AORs 0.50 and 0.78 respectively). Racial disparities persisted throughout the study period. Prevalence of fasting and vomiting/taking laxatives did not change between 1999 and 2013 for all races, while taking diet pills/powders/liquids decreased. Compared to individuals of normal weight who were accurate weight status perceivers, individuals of almost all other combinations of weight status and weight status perception had significantly higher odds of displaying any UDB outcome. Overestimation of weight status was found to be the strongest determinant of UDBs. Compared to individuals endorsing "not wanting to do anything" about their weight, individuals endorsing all other WCIs (including wanting to gain weight) also showed significantly higher odds for every UDB outcome, with wanting to lose weight having AORs of the greatest magnitudes.ConclusionsPrevalence of UDBs is persistently high, and highest among females across all racial groups. UDBs may elevate undesired weight gain and weight loss in individuals who are obese/overweight and underweight respectively. Further research into weight status perceptions among adolescents may inform efforts to reduce UDBs.

Effects of dietary protein levels on growth and body composition of juvenile (age-1) Black Buffalo Ictiobus niger

Populations of Black Buffalo Ictiobus niger, a broadly-distributed catostomid species native to the Mississippi River basin, are in decline, similar to many other catostomids. Artificial propagation and culture are frequently a part of native species recovery plans, and developing formulated diets is a critical component of these plans. However, studies establishing protein requirements for catostomids are limited, particularly for larger juvenile to sub-adult sizes, even though catostomids are commonly reared to these sizes. Therefore, we conducted a 10-week growth study to evaluate optimal protein levels in juvenile (age-1) Black Buffalo (mean ± SE: total length = 218.7 ± 0.8 mm, weight = 148.5 ± 1.6 g). Five practical diets were formulated to contain 30, 34, 38, 41, and 45% crude protein with each diet fed to four replicate tanks (400-L) containing 10 fish each. Fish fed a diet containing 41% crude protein had greater biomass gain (total weight gain for all fish in the tank) when compared to other diets. Individual weight gain (percent increase) was greater in fish fed diets containing 41% and 45% protein compared to lower protein diets. Results from this study suggest a diet with 41% crude protein would produce optimal growth for juvenile (age-1) Black Buffalo.

Sustained Physical Activity, NotWeightLoss, Associated With Improved Survival in CoronaryHeart Disease.

Individuals with coronary heart disease (CHD) are recommended to be physically active and to maintain a healthy weight. There is a lack of data on how long-term changes in body mass index (BMI) and physical activity (PA) relate to mortality in this population. This study sought to determine the associations among changes in BMI, PA, and mortality in individuals with CHD. The authors studied 3,307 individuals (1,038 women) with CHD from the HUNT (Nord-Trøndelag Health Study) with examinations in 1985, 1996, and 2007, followed until the end of 2014. They calculated the hazard ratio (HR) forall-cause and cardiovascular disease (CVD) mortality according to changes in BMI and PA, and estimated using Cox proportional hazards regression models adjusted for age, smoking, blood pressure, diabetes, alcohol, and self-reported health. There were 1,493 deaths during 30 years of follow-up (55% from CVD, median 15.7 years). Weight loss, classified as change in BMI<-0.10kg/m2/year, associated with increased all-cause mortality (adjusted HR: 1.30; 95% confidence interval [CI]: 1.12 to 1.50). Weight gain, classified as change in BMI≥0.10kg/m2/year, was not associated with increased mortality (adjusted HR: 0.97; 95% CI: 0.87 to 1.09). Weight loss only associated with increased risk in those who were normal weight at baseline (adjusted HR: 1.38; 95% CI: 1.11 to 1.72). There was a lower risk for all-cause mortality in participants who maintained low PA (adjusted HR: 0.81; 95% CI: 0.67 to 0.97) or high PA (adjusted HR: 0.64; 95% CI: 0.50 to 0.83), compared with participants who were inactive over time. CVD mortality associations were similar as for all-cause mortality. The study observed no mortality risk reductions associated with weight loss in individuals withCHD, and reduced mortality risk associated with weight gain in individuals who were normal weight at baseline. Sustained PA, however, was associated with substantial risk reduction.

Ethnic Differences in the Influence of Peers on Weight-Related Behavior

There is no doubt that peers have an influence on individual weight gain. This article seeks to find if the influence of peers is consistent across ethnic groups or whether certain groups are influenced more by their peers than other groups. Studies in the peer effects literature primarily focus on identifying the direct impact of peers on individual behavior. The difficulty in isolating the direct behavioral effect of peers on individual’s behavior is that there are several mechanisms driving the correlation between individual’s outcomes and peer group outcomes. We model peer effects using an identification strategy that exploits network structure and incorporates group-specific fixed effects to control for confounding effects. Using data taken from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we find that peer effects exist across all genders and ethnic groups, but it is more prevalent for Hispanic youth with respect to sedentary activities. The findings also show that having male peers is associated with lower exercise for both young males and young females. The implications of this study are that reducing obesity through encouraging healthy behaviors should not only focus on individual factors but also on the role of peers as well as gender and ethnic differences in the design of such programs.

Effects of supplementing sow diets with fermented corn and soybean meal mixed feed during lactation on the performance of sows and progeny.

In the present study, two experiments were performed to study the effects of feeding fermented corn and soybean meal mixed feed (FMF) with Bacillus subtilis and Enterococcus faecium to lactating sows on the performance of the sows and their progeny. In experiment 1, 60 sows were allocated to the following three dietary treatments: 1) sows fed a corn and soybean meal basal diet (control) from day 3 before parturition to weaning, 2) sows fed a diet with 7.5% FMF, and 3) sows fed a diet with 15% FMF. Results indicated that feeding 15% FMF significantly improved (P < 0.05) the sows' ADFI, the individual piglet weaning weights, and piglet weight gain and reduced (P < 0.05) the backfat loss of sows compared with the control group. However, the 7.5% FMF treatment did not alter the performance of the sows or their progeny. Therefore, we considered the level of 15% FMF to be more efficient than 7.5% FMF. To verify the results of experiment 1, we performed experiment 2, in which 60 sows at 111 d of gestation were allocated into the following two dietary treatments: 1) sows fed a basal lactation diet (control) from d 111 of gestation to weaning and 2) sows fed a basal diet with 15% FMF. Compared with the control group, 15% FMF inclusion significantly increased (P < 0.05) the sows' ADFI, litter weight gain, and individual piglet weight gain during lactation and markedly decreased the backfat loss of sows (P < 0.05) and piglet diarrhea incidence (P < 0.05). Additionally, the milk yield and IgA contents of the milk in sows fed 15% FMF were greater (P < 0.05) than those of the control group. Furthermore, the apparent total tract digestibility of GE, DM, and total P of sows was increased (P < 0.05) with 15% FMF supplementation. Therefore, the present study indicates that supplementing sow diets with 15% FMF from parturition to weaning has the potential to 1) increase sow ADFI, milk production, milk IgA content, and nutrient digestibility and promote sow reproductive performance by shortening the weaning-to-estrous interval and 2) promote the growth performance of their progeny and decrease diarrhea incidence.