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 yrs) 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.

Obesity and impaired glucose homeostasis in older adults place these individuals at risk for diabetes. Dehydration, glucose homeostasis, and insulin resistance are related; while aging and dehydration are associated with decreased glucose tolerance, weight loss can improve glycemia. For older adults following hypocaloric diets, additional water consumption may lead to greater weight loss. Further more, research suggests an association between insulin resistance and the body water retention hormone, arginine vasopressin (AVP). Analysis of the association between plasma copeptin (an AVP derivative) and fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) may provide further insight into the relationship between dehydration and diabetes risk. Our objective was to investigate the possibility that increased water consumption among older adults (n = 29, BMI = 31 ± 1 kg/m 2 , age = 62 ± 1 years) could improve glucose homeostasis beyond that observed with weight loss, as well as associations between plasma copeptin and diabetes risk. This retrospective analysis utilized data from a previous investigation, in which obese/overweight older adults were assigned to one of two groups: 1) Water: consume 500 ml of water prior to three daily meals over a 12-week hypocaloric diet intervention, or 2) Non-water: hypocaloric diet alone. In the present analysis, fasting plasma glucose and insulin, HOMA-IR, and plasma copeptin were evaluated, and compared to urinary specific gravity (USG), drinking water consumption, and body weight. Analyses performed using group assignment, volume of drinking water consumed or among a subgroup pair-matched for weight loss and sex did not reveal significant differences between groups. However in the full sample, plasma insulin concentration was associated with USG (r = 0.512, P < 0.01) and copeptin (r = 0.389, P < 0.05), and HOMA-IR was associated with USG (r = 0.530, P < 0.01) at week 12. Improvements in fasting insulin for water group participants (−8.5 +/− 4 pmol/L) were also detected. Associations between hydration and insulin resistance support the need for future investigations addressing hydration status and diabetes risk.