Interventions for improving metabolic risk in overweight Latino youth.

This review highlights various components of interventions that reduced obesity and type 2 diabetes risk factors among overweight Latino youth. A total of 114 overweight Latino adolescents completed one of four randomized controlled trials: 1) strength training (ST; boys only); 2) modified carbohydrate nutrition program (N); 3) combination of N+ST; or 4) N + Combination of Aerobic and ST (N+CAST; girls only). Measures included: strength by 1-repetition max, dietary intake by 3-d records, body composition by DEXA/MRI, glucose/insulin indices by oral and IV glucose tolerance tests. ST improved insulin sensitivity by 45% in Latino boys, and N, N+ST, and N+CAST improved glucose control in Latino boys and girls. The CAST approach reduced all adiposity measures by ∼3% in Latina girls. Participants who decreased added sugar, increased dietary fiber, and had increased parental attendance, regardless of intervention group, improved insulin action and reduced visceral adipose tissue. In conclusion, ST, CAST, and a modified carbohydrate nutrition program with separate parental classes were all successful components of the interventions that decreased obesity and related metabolic diseases.

Inverse relation between dietary fiber intake and visceral adiposity in overweight Latino youth.

BACKGROUND: To date, no studies have assessed the longitudinal changes of dietary intake on metabolic risk factors in Latino youth. OBJECTIVE: We assessed the relation between changes in dietary intake, specifically sugar and fiber intakes, with changes in adiposity and risk factors for type 2 diabetes in a longitudinal analysis of overweight Latino youth. DESIGN: Overweight Latino youth (n = 85; aged 11-17 y) underwent the following measures over 2 y [mean (+/-SD) time difference was 1.5 +/- 0.5 y]: dietary intake by 2-d diet recalls, body composition by dual-energy X-ray absorptiometry and magnetic resonance imaging, and glucose and insulin indexes by oral- and intravenous-glucose-tolerance tests. Partial correlations and repeated-measures analysis of covariance assessed the relation between changes in dietary intake with changes in adiposity and glucose and insulin indexes, independent of the following a priori covariates: sex, Tanner stage, time between visits, and baseline dietary and metabolic variables of interest. RESULTS: Increases in total dietary fiber (g/1000 kcal) and insoluble fiber (g/1000 kcal) were associated with decreases in visceral adipose tissue (VAT) (r = -0.29, P = 0.02, and r = -0.27, P = 0.03, for total dietary and insoluble fiber, respectively), independent of baseline covariates and change in subcutaneous abdominal adipose tissue. Participants who had decreased total dietary fiber (mean decrease of 3 g . 1000 kcal(-1) x d(-1)) had significant increases in VAT compared with participants who had increased total dietary fiber (21% compared with -4%; P = 0.02). No other changes in dietary variables were related to changes in adiposity or metabolic variables. CONCLUSION: Small reductions in dietary fiber intake over 1-2 y can have profound effects on increasing visceral adiposity in a high-risk Latino youth population.

Aerobic and strength training reduces adiposity in overweight Latina adolescents.

PURPOSE: To date, no study has examined the synergistic effects of a nutrition and combination of aerobic and strength training (CAST) on both adiposity and metabolic parameters in overweight Latina adolescent females. The goal was to assess if a 16-wk nutrition plus CAST pilot study had stronger effects on reducing adiposity and on improving glucose/insulin indices compared with control (C), nutrition only (N), and a nutrition plus strength training (N + ST) groups. METHODS: In a 16-wk randomized trial, 41 overweight Latina girls (15.2 +/- 1.1 yr) were randomly assigned to C (n = 7), N (n = 10), N + ST (n = 9), or N + CAST (n = 15). All intervention groups received modified carbohydrate nutrition classes (once a week), whereas the N + ST also received strength training (twice a week) and the N + CAST received a combination of strength and aerobic training (twice a week). The following were measured before and after intervention: strength by one repetition maximum, physical activity by the 7-d accelerometry and the 3-d physical activity recall, dietary intake by 3-d records, body composition by dual-energy x-ray absorptiometry (DEXA), glucose/insulin indices by oral glucose tolerance test, and intravenous glucose tolerance test with minimal modeling. Across intervention group, effects were tested using ANCOVA with post hoc pairwise comparisons. RESULTS: There were significant overall intervention effects for all adiposity measures (weight, body mass index [BMI], BMI z-scores, and DEXA total body fat), with a decrease of 3% in the N + CAST group compared with a 3% increase in the N + ST group (P < or = 0.05). There was also an intervention effect for fasting glucose with the N group increasing by 3% and the N + CAST group decreasing by 4% (P < or = 0.05). CONCLUSION: The CAST was more effective than nutrition alone or nutrition plus strength training for reducing multiple adiposity outcomes and fasting glucose in overweight Latina girls. However, further research investigating and identifying intervention approaches that improve both adiposity and insulin indices, particularly in high-risk populations, are warranted.

Association of breakfast skipping with visceral fat and insulin indices in overweight Latino youth.

Few studies have investigated the relationship between breakfast consumption and specific adiposity or insulin dynamics measures in children. The goal of this study is to determine whether breakfast consumption is associated with adiposity, specifically intra-abdominal adipose tissue (IAAT), and insulin dynamics in overweight Latino youth. Participants were a cross-sectional sample of 93 overweight (> or =85th percentile BMI) Latino youth (10-17 years) with a positive family history of type 2 diabetes. Dietary intake was assessed by two 24-h recalls, IAAT, and subcutaneous abdominal adipose tissue (SAAT) by magnetic resonance imaging, body composition by dual energy X-ray absorptiometry, and insulin dynamics by a frequently sampled intravenous glucose tolerance test and minimal modeling. Participants were divided into three breakfast consumption categories: those who reported not eating breakfast on either day (breakfast skippers; n = 20), those who reported eating breakfast on one of two days (occasional breakfast eaters; n = 39) and those who ate breakfast on both days (breakfast eaters; n = 34). Using analyses of covariance, breakfast omission was associated with increased IAAT (P = 0.003) independent of age, Tanner, sex, total body fat, total body lean tissue mass, and daily energy intake. There were no significant differences in any other adiposity measure or in insulin dynamics between breakfast categories. Eating breakfast is associated with lower visceral adiposity in overweight Latino youth. Interventions focused on increasing breakfast consumption are warranted.

Dietary intake and the metabolic syndrome in overweight Latino children.

Little is known about the relationship between diet and metabolic health in Latino children, a population at increased risk for diabetes. The present study evaluates diet composition and the metabolic syndrome in a cross-sectional sample of 109 overweight Latino children aged 10 to 17 years with a family history of type 2 diabetes. Dietary intake was assessed by two 24-hour recalls. Associations between nutrients and features of the metabolic syndrome were examined using multiple linear regression and analysis of covariance. Log cholesterol intake was positively associated with log systolic blood pressure (beta=0.034, P=0.017) and log soluble dietary fiber intake was inversely associated with log waist circumference (beta=-0.069, P=0.036). Log soluble fiber intake was significantly higher in participants with 0 features compared to those with 3+ features of the metabolic syndrome (P=0.046), which translates to 5.2 g vs 4.1 g soluble fiber daily. No other significant associations were found between dietary variables and either the individual features of the metabolic syndrome or the clustering of metabolic syndrome components. Increases in soluble fiber through the daily consumption of fruits, vegetables, and beans may improve metabolic health in Latino children.

Associations of dietary sugar and glycemic index with adiposity and insulin dynamics in overweight Latino youth.

BACKGROUND: Few studies have examined the relation between dietary carbohydrate quality, adiposity, and insulin dynamics in children. OBJECTIVE: The objective of the study was to determine which aspects of dietary carbohydrate, specifically dietary sugar, fiber, glycemic index, or glycemic load, are associated with adiposity and insulin dynamics in overweight Latino children. DESIGN: We examined 120 overweight Latino children (10-17 y old) with a family history of type 2 diabetes. Dietary intake was determined by repeated 24-h diet recalls. Adiposity was assessed by using total-body dual-energy X-ray absorptiometry. Insulin dynamics [insulin sensitivity (SI), acute insulin response, and disposition index (an index of beta-cell function)] were measured by using a frequently sampled intravenous-glucose-tolerance test. RESULTS: After adjustment for covariates, total sugar (g/d) was positively correlated with body mass index (BMI; in kg/m(2)), BMI z scores, and total fat mass (r = 0.20, r = 0.22, and r = 21, respectively; P < 0.05) and negatively correlated with SI and disposition index (r = -0.29 and r = -0.24, respectively; P < 0.05). Dietary fiber, glycemic index, and glycemic load were not significantly correlated with adiposity or insulin dynamics before or after control for covariates. Regression analyses showed that total sugar intake explained an additional 3.4%, 4.6%, and 2.4% of the variance in BMI, BMI z scores, and total fat mass, respectively, and an additional 5.6% and 4.8% of the variance in SI and disposition index (P < 0.05), respectively, after control for covariates. CONCLUSION: In this cohort, total sugar intake, rather than glycemic index or glycemic load, was associated with higher adiposity measures, lower SI, and lower measures of insulin secretion.

Feasibility of a home-based versus classroom-based nutrition intervention to reduce obesity and type 2 diabetes in Latino youth.

OBJECTIVES: The objectives of this pilot study were to compare the dietary, physiological and metabolic effects of 12-week modified carbohydrate nutrition intervention when disseminated in an individualized home-based format versus a group classroom-based format. METHODS: Twenty-three overweight (>/=85(th) percentile BMI) Latina adolescent females (12-17 years of age) were randomized to a 12-week modified carbohydrate dietary intervention delivered in either an individualized home-based format (n = 11) or a group classroom-based format (n = 12). Anthropometrics, dietary intake by 3-day diet records, insulin dynamics by extended 3-hour Oral Glucose Tolerance test (OGTT) and body composition by Dual energy X-ray absorptiometry (DXA) were measured before and after intervention; 24-hour diet recalls were collected once or twice per month throughout the program. RESULTS: Mixed modeling showed no significant differences in changes in dietary intake between intervention groups, but both groups significantly reduced intake of added sugar, sugary beverages and refined carbohydrates by 33%, 66%, and 35%, respectively, and dietary fiber significantly increased by 44% (p <0.01) throughout the 12 weeks. There was a significant time effect for BMI z-scores within each intervention group (p <0.05). There was no significant time*intervention group interaction for any of the physiological or metabolic variables, indicating that change over time was not significantly different between intervention groups. CONCLUSIONS: Although a culturally tailored, modified carbohydrate dietary intervention led to significant improvements in dietary intake and BMI z-scores, the extremely intensive, individualized, home-based program was no more effective at improving diet, decreasing adiposity or reducing type 2 diabetes risk factors than the traditional classroom-based format.