Guowen Cai

Low-Income, Overweight and Obese Mothers as Agents of Change to Improve Food Choices, Fat Habits, and Physical Activity in their 1-to-3-Year-Old Children

Objective: To examine the effects of a weight loss program for mothers on the diet and activity of mothers and their 1–3 year old children. Design: Overweight and obese mothers participated in an 8-week weight loss intervention encompassing diet, physical activity, and behavioral modification. Anthropometrics, demographic, dietary, and physical activity questionnaires were administered at weeks 0 and 8; anthropometrics were re-evaluated at week 24. Subjects: Mothers (N=91) of a 1–3 year old child; body mass index (BMI) ≥ 25 kg/m2; non-breastfeeding; age 18–45 years; income < 200% of federal poverty index; Hispanic, African American, or white; and English-speaking were recruited from Special Supplemental Program for Women Infants and Children (WIC) and public health clinics. Intervention Measures of Outcome: Weight loss in mothers and improvements in diet (reduction in calories, fat, snacks/desserts, sweetened beverages, and increases in fruit, vegetables) and activity in mothers and children. Results: Weight loss in mothers was modest (−2.7 kg, p < 0.001) and sustained at week 24 (−2.8 kg, p < 0.001), and children gained in height and weight as expected for normal growth (p < 0.001). Initial energy intakes of children exceeded Estimated Energy Requirements (123%) and were reduced to acceptable levels post-intervention (102%, p < 0.001); additional beneficial changes in childrens diets were decreased total (47.7 to 39.9 g/day) and saturated fat (19.2 to 16.6 g/day), high-fat snacks/desserts (1.6 to 0.9 servings/day), added fats (81.8 to 40.9% using), sweetened beverages (0.8 to 0.4 servings/day), and fast food consumption (11.6 to 6.6% of meals), and increased home-prepared meals (63.2 to 71.6% of meals) (p < 0.01 for all). Physical activity scores improved by 7% in children (p < 0.05). Comparable changes in food choices and activity also were seen in mothers. Conclusion: Offering weight loss classes was a successful method of enticing low-income women to participate in an educational intervention that benefited their children. Overweight and obese mothers who modified their food choices and fat habits made comparable changes for their child.

Evidence that multiple genetic variants of MC4R play a functional role in the regulation of energy expenditure and appetite in Hispanic children

BACKGROUNDnMelanocortin-4-receptor (MC4R) haploinsufficiency is the most common form of monogenic obesity; however, the frequency of MC4R variants and their functional effects in general populations remain uncertain.nnnOBJECTIVEnThe aim was to identify and characterize the effects of MC4R variants in Hispanic children.nnnDESIGNnMC4R was resequenced in 376 parents, and the identified single nucleotide polymorphisms (SNPs) were genotyped in 613 parents and 1016 children from the Viva la Familia cohort. Measured genotype analysis (MGA) tested associations between SNPs and phenotypes. Bayesian quantitative trait nucleotide (BQTN) analysis was used to infer the most likely functional polymorphisms influencing obesity-related traits.nnnRESULTSnSeven rare SNPs in coding and 18 SNPs in flanking regions of MC4R were identified. MGA showed suggestive associations between MC4R variants and body size, adiposity, glucose, insulin, leptin, ghrelin, energy expenditure, physical activity, and food intake. BQTN analysis identified SNP 1704 in a predicted micro-RNA target sequence in the downstream flanking region of MC4R as a strong, probable functional variant influencing total, sedentary, and moderate activities with posterior probabilities of 1.0. SNP 2132 was identified as a variant with a high probability (1.0) of exerting a functional effect on total energy expenditure and sleeping metabolic rate. SNP rs34114122 was selected as having likely functional effects on the appetite hormone ghrelin, with a posterior probability of 0.81.nnnCONCLUSIONnThis comprehensive investigation provides strong evidence that MC4R genetic variants are likely to play a functional role in the regulation of weight, not only through energy intake but through energy expenditure.

Principal component for metabolic syndrome risk maps to chromosome 4p in Mexican Americans: the San Antonio Family Heart Study.

Metabolic syndrome refers to the clustering of disease conditions such as insulin resistance, hyperinsulinemia, dyslipidemia, hypertension, and obesity. To explore the genetic predispositions of this complex syndrome, we conducted a principal components analysis using data on 14 phenotypes related to the risk of developing metabolic syndrome. The subjects were 566 nondiabetic Mexican Americans, distributed in 41 extended families from the San Antonio Family Heart Study. The factor scores obtained from these 14 phenotypes were used in multipoint linkage analysis using SOLAR. Factors were identified that accounted for 73% of the total variance of the original variables: body size-adiposity, insulin-glucose, blood pressure, and lipid levels. Each factor exhibited evidence for either significant or suggestive linkage involving four factor-specific chromosomal regions relating to chromosomes 1, 3, 4, and 6. Significant evidence for linkage of the lipid factor was found on chromosome 4 near marker D4S403 (LOD-3.52), where the cholecystokinin A receptor (CCKAR) and ADP-ribosyl cyclase 1 (CD38) genes are located. Suggestive evidence for linkage of the body size-adiposity factor to chromosome 1 near marker D1S1597 (LOD-2.53) in the region containing the nuclear receptor subfamily 0, group B, member 2 gene (NROB2) also was observed. The insulin-glucose and blood pressure factors were linked suggestively to regions on chromosome 3 near marker D3S1595 (LOD-2.20) and on chromosome 6 near marker D6S1031 (LOD-2.08), respectively. In summary, our findings suggest that the factor structures for the risk of metabolic syndrome are influenced by multiple distinct genes across the genome.

A nutrition and physical activity intervention promotes weight loss and enhances diet attitudes in low-income mothers of young children.

The purpose of this study was to evaluate a nutrition and physical activity program for reducing body weight and improving nutrition attitudes in mothers of young children. A convenience sample of 114 intervention mothers and 33 comparison mothers was recruited from public health clinics and community centers. Eligibility criteria included Hispanic, African American, or white ethnicity; body mass index of at least 25 kg/m(2); low income (< 200% of the federal poverty index); and youngest child aged 1 to 4 years. For intervention participants, height, weight, percentage of body fat, waist circumference, demographics, nutrition attitudes, and dietary intake were measured at weeks 0 and 8; height, weight, percentage of body fat, and waist circumference were reassessed at 6 months. Overweight mothers in the comparison group provided anthropometric and demographic data at weeks 0 and 8. Changes in anthropometrics, attitudes, and dietary intake were evaluated in intervention mothers. Anthropometric data of intervention vs comparison group mothers were examined. Differences in anthropometrics and attitude scores between weight loss responders (> or = 2.27 kg) and nonresponders (< 2.27 kg) were assessed at week 8. Intervention participants lost weight (x = -2.7 kg; P < .001), whereas comparison mothers gained a slight amount of weight (x = 0.1 kg) by week 8. Weight loss responders had healthier eating attitudes (5.6 vs 5.2; P < .01) and fewer perceived barriers (2.4 vs 2.9; P < .05) than nonresponders postintervention. In conclusion, this dietary and physical activity curriculum is a valuable resource for weight management programs serving low-income women.

Short-term weight loss in overweight/obese low-income women improves plasma zinc and metabolic syndrome risk factors.

Metabolic syndrome is a group of disorders involving obesity, insulin resistance, dyslipidemia and hypertension. Obesity is the most crucial risk factor of metabolic syndrome, because it is known to precede other risk factors. Obesity is also associated with disturbances in the metabolism of the trace mineral, zinc. The overall purpose of this study was to investigate the effects of short-term weight loss on plasma zinc and metabolic syndrome risk factors. An 8-week weight loss intervention study was conducted with 90 low-income overweight/obese mothers, whose youngest child was 1-3 years old. Plasma levels of zinc, glucose, insulin, leptin, triglycerides, total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol were measured and compared at weeks 0 and 8 of the weight loss program. At pre-study, plasma zinc was low in 39% and, within normal values in 46%, of obese/overweight mothers. By the end of intervention, plasma zinc rose by 22% and only 5% of the mothers continued to exhibit low plasma zinc. At post-study, the metabolic syndrome risk factors of waist circumference, HDL cholesterol, and diastolic blood pressure (p<0.05) showed significant improvements. Plasma zinc increased by a greater margin (67%) in women with low zinc, as compared to those with normal zinc (18%); weight reduction was similar in both the groups. Finally, changes in % body fat were related negatively with changes in plasma zinc (r=- 0.28, p<0.05). The circulating levels of zinc, as well as the metabolic syndrome components, showed significant improvements in overweight/obese low-income women after weight loss.