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Background: Aerobic exercise interventions have been shown to result in alterations to dietary intake and non-exercise physical activity (PA). To date, the ability for resistance training (RT) to influence other health-related behaviors has not been examined. This study aimed to determine if initiation and maintenance of RT is associated with spontaneous changes in dietary quality and non-RT PA in adults with prediabetes., Methods: Overweight/obese adults (n=170, BMI=32.9±3.8kg·m 2 , age=59.5±5.5years, 73% female) with prediabetes were enrolled in the 15-month Resist Diabetes trial. Participants completed a supervised 3-month RT initiation phase followed by a 6-month maintenance phase and a 6-month no-contact phase. Participants were not encouraged to change eating or non-RT PA behaviors. At baseline, and months 3, 9, and 15, three 24-hour diet recalls were collected to evaluate dietary intake and quality, the Aerobics Institute Longitudinal Study Questionnaire was completed to evaluate non-RT PA, and body mass, body composition (DXA), and muscular strength were measured. At months 3, 9, and 15 social cognitive theory (SCT) constructs were assessed with a RT Health Beliefs Questionnaire. Mixed effects models were used to assess changes in dietary intake and non-RT PA over the 15-month study period., Results: Energy and carbohydrate intake decreased with RT initiation and maintenance phases (baseline to month 9: β=-87.9, p=0.015 and β=-16.3, p<0.001, respectively). No change in overall dietary quality (Healthy Eating Index [HEI]-2010 score: β=-0.13, p=0.722) occurred, but alterations in HEI-2010 sub-scores were detected. Maintenance of RT was accompanied by an increase in MET-min/week of total non-RT PA (month 3 to month 9: β=146.2, p=0.01), which was predicted by increased self-regulation and decreased negative outcome expectancies for RT (β=83.7, p=0.014 and β=-70.0, p=0.038, respectively)., Conclusions: Initiation and maintenance of RT may be a gateway behavior leading to improvements in other health-related behaviors. These results provide rationale for single-component lifestyle interventions as an alternative to multi-component interventions, when resources are limited., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: To determine whether a social cognitive theory (SCT)-based intervention improves resistance training (RT) maintenance and strength, and reduces prediabetes prevalence., Research Design and Methods: Sedentary, overweight/obese (BMI: 25-39.9 kg/m2) adults aged 50-69 (N = 170) with prediabetes participated in the 15-month trial. Participants completed a supervised 3-month RT (2×/wk) phase and were randomly assigned (N = 159) to one of two 6-month maintenance conditions: SCT or standard care. Participants continued RT at a self-selected facility. The final 6-month period involved no contact. Assessments occurred at baseline and months 3, 9, and 15. The SCT faded-contact intervention consisted of nine tailored transition (i.e., supervised training to training alone) and nine follow-up sessions. Standard care involved six generic follow-up sessions. Primary outcomes were prevalence of normoglycemia and muscular strength., Results: The retention rate was 76%. Four serious adverse events were reported. After 3 months of RT, 34% of participants were no longer prediabetic. This prevalence of normoglycemia was maintained through month 15 (30%), with no group difference. There was an 18% increase in the odds of being normoglycemic for each % increase in fat-free mass. Increases in muscular strength were evident at month 3 and maintained through month 15 (P<0.001), which represented improvements of 21% and 14% for chest and leg press, respectively. Results did not demonstrate a greater reduction in prediabetes prevalence in the SCT condition., Conclusions: Resistance training is an effective, maintainable strategy for reducing prediabetes prevalence and increasing muscular strength. Future research which promotes RT initiation and maintenance in clinical and community settings is warranted., Trial Registration: ClinicalTrials.gov NCT01112709.

Prediabetes is associated with low-grade chronic inflammation that increases the risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). An elevated lipopolysaccharide concentration, associated with dysbiosis of the intestinal microbiota, has been implicated in the development of both T2D and CVD. Selective modulation of the intestinal microbiota with prebiotics reduces intestinal permeability and endotoxin concentrations, inflammation, and metabolic dysfunction in rodents. The effect of prebiotic supplementation on cardio-metabolic function in humans at risk for T2D is not known. The primary aim of this trial is to determine the influence of prebiotic supplementation with inulin on insulin sensitivity and skeletal muscle metabolic flexibility in adults at risk for T2D. We hypothesize that prebiotic supplementation with inulin will improve insulin sensitivity and skeletal muscle metabolic flexibility. We will randomize 48 adults (40-75 yrs) with prediabetes or a score ≥ 5 on the American Diabetes Association (ADA) risk screener to 6 weeks of prebiotic supplementation with inulin (10 g/day) or placebo. Subjects will be provided with all food for the duration of the study, to avoid potential confounding through differences in dietary intake between individuals. Intestinal permeability, serum endotoxin concentrations, insulin sensitivity, skeletal muscle metabolic flexibility, endothelial function, arterial stiffness, and fecal bacterial composition will be measured at baseline and following treatment. The identification of prebiotic supplementation with inulin as an efficacious strategy for reducing cardio-metabolic risk in individuals at risk of T2D could impact clinical practice by informing dietary recommendations and increasing acceptance of prebiotics by the scientific and medical community., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Engagement in one type of health behavior change may exert a "spillover" effect resulting in other behavior changes. Few studies have examined dietary intake following prolonged training, and none have evaluated spontaneous dietary changes beyond alterations in energy or macronutrient intake following initiation of strength/resistance training (RT). The purpose of this observational investigation was to determine if spontaneous dietary intake modifications occur in response to initiation of an RT program, among older adults. Previously sedentary adults with prediabetes (n=134, age=59±1 years) were enrolled in a supervised 12-week RT program. Participants were not given dietary advice or encouraged to change eating behaviors. Three non-consecutive 24-hour dietary recalls were collected at baseline and after 12 weeks of RT. Reductions in intake of energy (1914±40 kcal vs. 1834±427 kcal, p=0.010), carbohydrate (211.6±4.9 g vs. 201.7±5.2 g, p=0.015), total sugar (87.4±2.7 g vs. 81.5±3.1 g, p=0.030), glycemic load (113.4±3.0 vs. 108.1±3.2, p=0.031), fruits and vegetables (4.6±0.2 servings vs. 4.1±0.2 servings, p=0.018), and sweets and desserts (1.1±0.07 servings vs. 0.89±0.07 servings, p=0.023) were detected over time. No changes in other dietary intake variables were observed. Mode of exercise and disease state may be important factors in determining whether dietary modifications occur with exercise initiation, among previously sedentary adults. Successful initiation of RT may represent an opportunity for health care professionals to promote beneficial changes in dietary habits, among older adults with prediabetes., (Copyright © 2014 Elsevier Ltd. All rights reserved.)