Roseann M. Lyle

Dairy Calcium is Related to Changes in Body Composition during a Two-Year Exercise Intervention in Young Women

Objective: Relationships between micronutrients and dairy product intake and changes in body weight and composition over two years were investigated. Design: Two year prospective non-concurrent analysis of the effect of calcium intake on changes in body composition during a two year exercise intervention. Subjects: 54 normal weight young women, 18 to 31 years of age. Measures of Outcome: Mean intakes of nutrients of interest were determined from three-day diet records completed at baseline and every six months for two years. The change in total body weight and body composition (assessed by dual x-ray absorptiometry) from baseline to two years was also determined. Results: Total calcium/kilocalories and vitamin A together predicted (negatively and positively, respectively) changes in body weight (R2 = 0.19) and body fat (R2 = 0.27). Further, there was an interaction of calcium and energy intake in predicting changes in body weight, such that, only at lower energy intakes, calcium intake (not adjusted for energy) predicted changes in body weight. Conclusions: Regardless of exercise group assignment, calcium adjusted for energy intake had a negative relationship and vitamin A intake a positive relationship with two year changes in total body weight and body fat in young women aged 18 to 31 years. Thus, subjects with high calcium intake, corrected by total energy intake, and lower vitamin A intake gained less weight and body fat over two years in this randomized exercise intervention trial.

Calcium and Dairy Product Modulation of Lipid Utilization and Energy Expenditure

Objective: The purpose of this study was to investigate the impact of dietary calcium or dairy product intake on total energy expenditure (TEE), fat oxidation, and thermic effect of a meal (TEM) during a weight loss trial.

Previous physical activity relates to bone mineral measures in young women

Exercise may increase accretion of bone, potentially reducing the risk of osteoporosis. Previous physical activity was assessed in 204 minimally active young women (18-31 yr). Bone mineral content (BMC) and bone mineral density (BMD) for the total body, femoral neck, and spine were assessed by a dual x-ray absorptiometer, and the radius by a single photon absorptiometer. Self-reported occupation and leisure activity for the 5 yr before enrollment in the study, as well as high school and college sports participation, were assigned energy expenditure (EE) values. From this information, EE variables were created as follows: 1) occupation EE + leisure EE + high school sport and/or college sport EE if within prior 5 yr (5-yr EE); 2) occupation EE + leisure EE (occupation + leisure EE); and 3) high school sport EE (high school EE). These variables were correlated with bone mineral measures and significant results follow (P < 0.05). Five-year EE and occupation + leisure EE correlated with all measures of bone health (r from 0.13 to 0.39). High school EE correlated with total body BMD (r = 0.25) and BMC (r = 0.28), femoral neck BMD (r = 0.28), radius BMC (r = 0.20), as well as spine BMD (r = 0.20) and BMC (r = 0.27). When weight was controlled, 5-yr EE and occupation + leisure EE remained correlated with all BMC measures (r from 0.14 to 0.22). When controlled for weight, high school EE remained associated with femoral neck BMD (r = 0.24), total body BMD (r = 0.20) and BMC (r = 0.26), and spine BMC (r = 0.17). To partially control for selection bias, data were also controlled for total body BMD. Five-year EE and occupation + leisure EE remained positively correlated with all measures of BMC. High school EE remained correlated both with femoral neck BMD and total body BMC. In multiple regression analyses, 5-yr EE or occupation + leisure EE were significant predictors of all measures of bone health, except femoral neck BMD. High school EE was a significant predictor for total body BMD and BMC, femoral neck BMD, and spine BMC.

Peak spine and femoral neck bone mass in young women

Achievement of higher peak bone mass early in life may play a critical role against postmenopausal bone loss. Bone mineral density (BMD) of the spine, femoral neck, greater trochanter, Wards triangle, and spine bone mineral content (BMC) and bone surface area (BSA) were assessed by dual energy x-ray absorptiometry in 300 healthy females (age 6-32 years). Bone measurements were described by using nonlinear models with age, weight, height, or dietary calcium intake as the explanatory variables. At the spine, femoral neck, greater trochanter, and Wards triangle, the highest BMD level was observed at 23.0 +/- 1.4, 18.5 +/- 1.6, 14.2 +/- 2.0, and 15.8 +/- 2.1 years, respectively. The age of attaining peak spine BMC and BSA cannot be estimated, as significant increases in these two measures were observed through this age group. Age, weight, and height were all significant predictors of all these bone measurements. Weight was a stronger predictor than age for all sites. Dietary calcium intake was not a significant predictor for any of these bone measurements. We conclude that age of attaining peak bone mass at the hip is younger than at the spine, and BMC and BSA at the spine continue to increase through the early thirties in females.

Impact of exercise on bone health and contraindication of oral contraceptive use in young women.

PURPOSE The effect of quantified resistance and high impact exercise training on bone mass as modified by age and oral contraceptive (OCont) use in young women was studied. METHODS Women were categorized by age (18-23 vs 24-31 yr) and OCont use, and were then randomized into either three sessions of resistance exercise plus 60 min.wk-1 of jumping rope or a control group for 24 months. Total body, spine, femoral neck, greater trochanter, Wards area, and radial bone mineral density (BMD) and/or content (BMC), biochemical markers of bone turnover, dietary intake of calcium, lean body mass, maximal oxygen uptake, and strength were determined at baseline and every 6 months. RESULTS Total body (TB) BMC percent change from baseline was higher in exercisers compared with nonexercisers at 6 and 24 months. OCont users had lower bone turnover at baseline and a decrease in TBBMC from baseline compared with non-OCont users at 24 months. Spine BMC and BMD decreased in the exercise and OCont group at 6 months and remained significantly below nonexercisers who used oral contraceptives at 2 yr. Femoral neck BMD also decreased in the exercise and oral contraceptive group at 6 months. CONCLUSIONS Exercise prevented a decline in TBBMC seen in the nonexercisers. On the other hand, exercise in oral contraceptive users prevented the increase observed in the spine of the nonexercise plus OCont group.

Loneliness, emotional repression, marital quality, and major life events in women who develop breast cancer.

Women awaiting mammograms at a breast clinic were given questionnaires to investigate the role of psychosocial variables in the development of breast cancer while controlling for established breast cancer risk factors. Questionnaires to determine loneliness, emotional repression, marital quality, and major life changes were completed by 826 female volunteers who were later classified into groups according to their diagnoses. The total emotional repression score showed a hierarchy of most repression to least repression for the most-diseased to the most-healthy subjects. A breakdown of the emotional repression scale revealed that each group was significantly different from the other in suppression of anger and unhappiness. Women in the new cancer group showed significantly more loneliness than the women in the fibrocystic and normal groups. The newly diagnosed cancer group also had a higher proportion of women who experienced the death of a spouse or close family member within the past two years compared to the other groups.

Effect of 1-Year Dairy Product Intervention on Fat Mass in Young Women: 6-Month Follow-up

Objective: Previous results from this laboratory suggest that a 1‐year dairy intake intervention in young women does not alter fat mass. The objective of this study was to determine the impact of the 1‐year dairy intervention 6 months after completion of the intervention.

Exercise and oral contraceptive use suppress the normal age-related increase in bone mass and strength of the femoral neck in women 18–31 years of age

Women who exercise during their second and third decades may increase their peak bone mass and lower their eventual risk for postmenopausal fracture. However, the effects of exercise in younger women can be modulated by the use of oral contraceptives, which may prevent the normal accretion of bone mass that would otherwise occur. We hypothesized that exercise intervention in young adult women would significantly increase both bone mass and the bending rigidity of the femoral neck. We further hypothesized that exercise intervention in the presence of oral contraceptive use would have a negative effect on bone mass and bending rigidity. Women 18-31 years of age (n = 123) were classified by oral contraceptive use (OC, NOC) and age (18-23, 24-31 years), and then randomized into exercise or nonexercise groups. The exercise protocol consisted of three sessions/week of aerobic and nonaerobic exercises, and continued for 2 years. Each 6 months, the femoral neck of each subject was scanned using a Lunar dual-energy X-ray absorptiometry (DEXA) scanner, and bone mineral content, density and geometric information were used to calculate estimated stresses and bending rigidity at the hip. Percent changes from baseline were analyzed using two-way analysis of variance (ANOVA) at 6, 12, 18, and 24 months. Women who neither exercised nor took oral contraceptives (NE/NOC) had the greatest percentage increases in cross-sectional area (4.98 +/- 2.29%), cross-sectional moment of inertia (9.45 +/- 2.37%), total bone mineral density (2.07 +/- 2.09%), fracture index (8.03 +/- 2.03%), and safety factor (20.03 +/- 5.79%) over the 24 month exercise program. Women who exercised and did not take oral contraceptives (E/NOC) declined on most variables related to femoral strength and bone mass, whereas those women who took oral contraceptives were usually intermediate between NE/NOC and E/NOC, whether they exercised or not. These data show that either exercise or OC use is associated with a suppression of the normal increase in bone mass and mechanical strength in the femoral neck in women 18-31 years old, but the combination of exercise and OC use appears to have a less suppressive effect.

Protein Intake during Energy Restriction: Effects on Body Composition and Markers of Metabolic and Cardiovascular Health in Postmenopausal Women

Objective: The primary aim of this study was to assess the effects of dietary protein intake on energy restriction (ER)-induced changes in body mass and body composition. Clinical markers of metabolic and cardiovascular diseases were also measured. Design: 54 postmenopausal women, age 58 ± 2 y, body mass index 29.6 ± 0.8 kg/m2, were assigned to one of four groups. For 9 weeks, three ER groups ate a 1000 kcal/d lacto-ovo vegetarian basal diet plus 250 kcal/d of either beef (BEEF, n = 14), chicken (CHICKEN, n = 15), or carbohydrate/fat foods (CARB (lacto-ovo), n = 14), while a control group (CON, n = 11) consumed their habitual diets. Results: Energy intake was lower in the ER groups compared to CON (BEEF, 1114 ± 155 kcal/d, CHO: PRO: FAT, 46:24:30 % of energy intake; CHICKEN, 1098 ± 203 kcal/d, 51:25:24; CARB 1158 ± 341 kcal/d, 59:17:24; CON, 1570 ± 633 kcal/d, 47:20:33), but did not differ among ER groups. For all ER subjects combined, body mass (−6.7 ± 2.4 kg, 9 %), fat mass (−4.6 ± 1.9 kg, 13 %), and fat-free mass (−2.1 ± 1.1 kg, 5 %) decreased. These responses did not differ among the ER groups, except for body mass (CHICKEN −7.9 ± 2.6 kga; BEEF −6.6 ± 2.7 kga,b; CARB −5.6 ± 1.8 kgb; CON −1.2 ± 1.2 kgc; values with a difference superscript differ, p < 0.05). From PRE (week 0) to POST (week 9), total and LDL cholesterol decreased ∼12%, with no differences among groups. Triacylglycerol, HDL cholesterol, C-reactive protein (CRP), glucose, insulin, leptin, and adiponectin were not changed over time or differentially affected by diet. Conclusions: Overweight postmenopausal women can achieve significant weight loss and comparable short-term improvements in body composition and lipid-lipoprotein profile by consuming either a moderate-protein (25% of energy intake) poultry- or beef-containing diet or a lacto-ovo vegetarian protein (17% of energy intake) diet.

Psychosocial and environmental factors associated with dog-walking

Dog walking is associated with higher levels of physical activity (PA). However, not all dog owners walk their dog(s) at a level sufficient for health benefits. Therefore, identifying correlates of dog-walking may help to inform the design of more effective interventions to promote this specific form of PA. The purpose of this study was to examine psychosocial and environmental correlates of dog-walking and relationships of dog-walking with overall PA. In 2010, 391 dog owners (mean age = 43.6 ± 12.3 years) completed a survey. Multiple logistic regression and structural equation modeling were used to examine psychosocial and environmental correlates of dog-walking status, weekly minutes of dog-walking, and relationships of dog-walking with overall PA. Self-efficacy for dog-walking, dog-related outcome expectancies, family social support, dog social support, and neighborhood walking environment were associated with a 1.3–5.6 greater odds of being a dog walker. Self-efficacy mediated relationships between family support, dog support, and presence of a yard and dog-walking. Neighborhood environment, including the presence of greenery and trails, was also positively associated with duration of dog-walking (β = 0.17; p < 0.05). Every 30-minute increase in dog-walking was associated with a 23% greater odds of meeting PA guidelines by walking. Individual, social, and environmental factors consistent with a social–ecological framework were positively associated with dog-walking. Individuals were more likely to meet PA guidelines if they walked their dog(s) and engaged in dog-walking for longer duration.