Physical Activity Across the Curriculum (PAAC): a randomized controlled trial to promote physical activity and diminish overweight and obesity in elementary school children.

BACKGROUND: Physical Activity Across the Curriculum (PAAC) was a three-year cluster randomized controlled trial to promote physical activity and diminish increases in overweight and obesity in elementary school children. METHODS: Twenty-four elementary schools were cluster randomized to the Physical Activity Across the Curriculum intervention or served as control. All children in grades two and three were followed to grades four and five. Physical Activity Across the Curriculum promoted 90 min/wk of moderate to vigorous intensity physically active academic lessons delivered by classroom teachers. Body Mass Index was the primary outcome, daily Physical activity and academic achievement were secondary outcomes. RESULTS: The three-year change in Body Mass Index for Physical Activity Across the Curriculum was 2.0+/-1.9 and control 1.9+/-1.9, respectively (NS). However, change in Body Mass Index from baseline to 3 years was significantly influenced by exposure to Physical Activity Across the Curriculum. Schools with > or =75 min of Physical Activity Across the Curriculum/wk showed significantly less increase in Body Mass Index at 3 years compared to schools that had <75 min of Physical Activity Across the Curriculum (1.8+/-1.8 vs. 2.4+/-2.0, p=0.02). Physical Activity Across the Curriculum schools had significantly greater changes in daily Physical activity and academic achievement scores. CONCLUSIONS: The Physical Activity Across the Curriculum approach may promote daily Physical activity and academic achievement in elementary school children. Additionally, 75 min of Physical Activity Across the Curriculum activities may attenuate increases in Body Mass Index.

Minimal resistance training improves daily energy expenditure and fat oxidation.

UNLABELLED: Long-term resistance training (RT) may result in a chronic increase in 24-h energy expenditure (EE) and fat oxidation to a level sufficient to assist in maintaining energy balance and preventing weight gain. However, the impact of a minimal RT program on these parameters in an overweight college-aged population, a group at high risk for developing obesity, is unknown. PURPOSE: We aimed to evaluate the effect of 6 months of supervised minimal RT in previously sedentary, overweight (mean +/- SEM, BMI = 27.7 +/- 0.5 kg x m(-2)) young adults (21.0 +/- 0.5 yr) on 24-h EE, resting metabolic rate (RMR), sleep metabolic rate (SMR), and substrate oxidation using whole-room indirect calorimetry 72 h after the last RT session. METHODS: Participants were randomized to RT (one set, 3 d x wk(-1), three to six repetition maximums, nine exercises; N = 22) or control (C, N = 17) groups and completed all assessments at baseline and at 6 months. RESULTS: There was a significant (P < 0.05) increase in 24-h EE in the RT (527 +/- 220 kJ x d(-1)) and C (270 +/- 168 kJ x d(-1)) groups; however, the difference between groups was not significant (P = 0.30). Twenty-four hours of fat oxidation (g x d(-1)) was not altered after RT; however, reductions in RT assessed during both rest (P < 0.05) and sleep (P < 0.05) suggested increased fat oxidation in RT compared with C during these periods. SMR (8.4 +/- 8.6%) and RMR (7.4 +/- 8.7%) increased significantly in RT (P < 0.001) but not in C, resulting in significant (P < 0.001) between-group differences for SMR with a trend for significant (P = 0.07) between-group differences for RMR. CONCLUSION: A minimal RT program that required little time to complete (11min per session) resulted in a chronic increase in energy expenditure. This adaptation in energy expenditure may have a favorable impact on energy balance and fat oxidation sufficient to assist with the prevention of obesity in sedentary, overweight young adults, a group at high risk for developing obesity.

Weight loss and maintenance outcomes using moderate and severe caloric restriction in an outpatient setting.

The objective of this study was to determine if a formula diet of 520 kilocalorie (kcal, 2177 kilojoules [kJ]) compared to 850 kcal (3558 kJ) produces significantly greater weight loss and improved weight maintenance in a clinical outpatient setting. The investigation was a retrospective analysis of data from 1887 participants who underwent weight loss between December 1994 and January 2003. Participants were between the ages of 18 and 70 and completed a minimum of 12 weeks of a very-low-energy diet (VLED; 520 kcal) or a low-energy diet (LED; 850 kcal). Participants attended weekly meetings, were weighed, and received instruction in behavioral skills. Following active weight loss, participants transitioned to weight maintenance and were prescribed an individual structured meal plan aimed at maintaining body weight. Both levels of energy intake produced significant weight loss over 12 weeks (P < 0.05). Weight loss was 15.2 +/- 4.1% and 14.3 +/- 3.7% of initial body weight for participants in the VLED (n = 1231) and LED (n = 656), respectively. After controlling for baseline body weight, there was no significant difference between diets. Similarly, there was no significant difference in weight regain between VLED and LED after 12, 24, 36, and 48 weeks of weight maintenance. VLED did not produce a greater weight loss than the LED. LED provides similar weight loss with a lower incidence of adverse events and diminished need for medical monitoring. We conclude LED is an efficacious, safe, and less burdensome diet compared to VLED.

Changes in resting metabolic rate and substrate oxidation after 16 months of exercise training in overweight adults.

PURPOSE: To determine whether 16 months of moderate-intensity exercise training changes resting metabolic rate (RMR) and substrate oxidation in overweight young adults. METHODS: Participants were randomly assigned to nonexercise control (CON, 18 women, 15 men) or exercise (EX, 25 women, 16 men) groups. EX performed supervised and verified exercise 3-5 d/wk, 20-45 min/session, at 60-75% of heart-rate reserve. Body mass and composition, maximal oxygen consumption (VO2max), RMR, and resting substrate oxidation were assessed at baseline and after 9 and 16 months of training. RESULTS: EX men had significant decreases from baseline to 9 months in body mass (94.6+/-12.4 to 89.2+/-9.5 kg) and percent fat (28.3+/-4.6 to 24.5+/-3.9). CON women had significant increases in body mass (80.2+/-8.1 to 83.2+/-9.2 kg) from baseline to 16 months. VO2max increased significantly from baseline to 9 months in the EX men (3.67+/-0.62 to 4.34+/-0.58 L/min) and EX women (2.53+/-0.32 to 3.03+/-0.42 L/min). RMR increased from baseline to 9 months in EX women (1,583+/-221 to 1,692+/-230 kcal/d) and EX men (1,995+/-184 to 2,025+/-209 kcal/d). There were no significant differences within genders for either EX or CON in fat or carbohydrate oxidation. Fat oxidation was significantly higher for women than for men at 9 months in both CON and EX groups. CONCLUSIONS: Regular moderate-intensity exercise in healthy, previously sedentary overweight and obese adults increases RMR but does not alter resting substrate oxidation. Women tend to have higher RMR and greater fat oxidation, when expressed per kilogram fat-free mass, than men.

Alteration of dietary fat intake to prevent weight gain: Jayhawk Observed Eating Trial.

OBJECTIVE: To examine the effects of ad libitum diets with three distinct levels of fat intake for the prevention of weight gain in sedentary, normal-weight and overweight men and women. METHODS AND PROCEDURES: Three hundred and five participants were randomized to one of three diets. The diets targeted <25% of energy from fat (low fat (LF)), between 28 and 32% of energy from fat (moderate fat (MF)), or >35% of energy from fat (high fat (HF)). Participants consumed two meals per day on weekdays and one meal per day on weekends in a university cafeteria over a 12-week period. Energy and nutrient content of cafeteria foods were measured by digital photography. All meals and snacks consumed outside the cafeteria were measured by dietary recall. All analysis of energy and nutrient content was completed using Nutrition Data System for Research (NDS-R) version 2005. RESULTS: Two hundred and sixty participants completed the study. LF gained 0.1 +/- 3.1 kg, MF gained 0.8 +/- 2.5 kg, and HF gained 1.0 +/- 2.2 kg and there was no gender or age effect. Longitudinal mixed modeling indicated a significant difference among the groups in weight over time (P = 0.0366). When adjusting for total energy intake, which was a significant predictor of weight over time, the global effect for the group was eliminated. Thus, increasing weight was a function of increasing energy but not increasing percentage of fat intake. DISCUSSION: Energy intake, but not percentage of energy from fat, appears responsible for the observed weight gain. LF diets may contribute to weight maintenance and HF diets may promote weight gain due to the influence of fat intake on total energy intake.

Physical activity across the curriculum (PAAC): rationale and design.

BACKGROUND: Over the years schools have reduced physical education and recess time in favor of more academic instruction. Due to the drastic rise in obesity levels among children, some states have begun to mandate minimum amounts of physical activity (PA) that school children receive, causing schools to find alternative methods for increasing PA levels. Physical Activity Across the Curriculum (PAAC) is a 3-year randomized clinical trial incorporating moderate-intensity PA in elementary schools to reduce childhood obesity. This paper describes the rational, design, and methods of the PAAC intervention study. METHODS: Twenty-two elementary schools were randomized to either a control or intervention condition. In schools randomized to the intervention condition (PAAC), regular classroom teachers were taught how to incorporate PA into standard academic lessons. Teachers were asked to accumulate 90-100 min/week of PAAC each week through out the 3-year study period. Schools randomized to the control group did not alter their teaching methods. Direct observation of PA levels in the classroom was collected weekly. Height and weight was measured twice a year to calculate BMI. RESULTS: Two years of the intervention have been completed and only one school has left the study. The remaining 21 schools are participating in the final intervention year. CONCLUSIONS: The results from the PAAC intervention may provide schools with an alternative method to increase PA levels in children and reduce childhood obesity.

Impact of different levels of weight loss on blood pressure in overweight and obese women.

This study sought to determine the impact of different levels of weight loss on blood pressure in overweight/obese women. One hundred fifty-nine overweight/obese women (age 48.7 +/- 9.7, weight 101.3 +/- 18.7 kg, BMI 37.3 +/- 6.6 kg/m(2)) completed a six-month clinical weight loss program that included weekly nutrition, behavior, and exercise instruction. Participants consumed a very-low-energy diet (VLED) for 12 weeks. VLED was followed by four weeks of gradual reintroduction to solid foods. At week 16, participants received a diet to maintain weight or slightly reduce weight (<0.5 lb/week) which they followed for the duration of the study. All lab and blood pressure assessments were performed at baseline and six months. Three groups were formed according to the proportion of weight loss after six months; Group 1 had < 10% (n = 19), Group 2 had 10%-20% (n = 64), and Group 3 had >20% (n = 76) weight loss. Differences in systolic blood pressure (mm Hg) were found in dose response fashion for weight loss at six months with 125 +/- 17 (<10%), 119 +/- 13 (10%-20%), and 117 +/- 15 (>20%; p = 0.005). Differences in diastolic blood pressure (mm Hg) were also found in dose response fashion with 81 +/- 9 (<10%), 77 +/- 9 (10%-20%), and 75 +/- 9 (20%; p = 0.003). These data indicate that increasing weight loss beyond 10% of initial body weight may provide added improvements in blood pressure compared to less than 10% weight loss in overweight or obese women.

A comparison of meal replacements and medication in weight maintenance after weight loss.

OBJECTIVE: To compare the use of meal replacements or medication during weight maintenance subsequent to weight loss using a very low-energy diet (VLED) in overweight or obese adults. DESIGN: Participants followed a liquid VLED of 2177 kJ for 12 weeks followed by 4 weeks of re-orientation to solid foods. Participants were randomized at week 16 to receive either meal replacements or Orlistat both combined with a structured meal plan containing an energy value calculated to maintain weight loss. SUBJECTS: Sixty-four women (age = 49.9 +/- 10 y, weight = 101.6 +/- 17.1 kg, height = 164.9 +/- 6.0 cm, BMI = 36.7 +/- 5.4 kg/m(2)) and 28 men (age = 53.7 +/- 9.6 y, weight = 121.8 +/- 16.0 kg, height = 178.7 +/- 5.6 cm, BMI = 37.8 +/- 4.9 kg/m(2)) completed a 1 year weight management program. Behavioral weight management clinics included topics on lifestyle, physical activity (PA), and nutrition. Participants met for 90 min weekly for 26 weeks, and then biweekly for the remaining 26 weeks. OUTCOMES: Minutes of PA, fruits and vegetables (FV), and pedometer steps were recorded on a daily basis and reported at each group meeting. Body weight was obtained at each group meeting. RESULTS: During VLED, the MR group decreased body weight by 22.8 +/- 6.1 kg and the Orlistat group decreased body weight by 22.3 +/- 6.1 kg. During weight maintenance, there was no significant group by time interaction for body weight, PA, FV consumption, or pedometer steps. At week 16, the meal replacement group had a body weight of 85.4 +/- 14.3 kg that increased to 88.1 +/- 16.5 kg at 52 weeks (p < 0.05). At week 16, the Orlistat group had a body weight of 85.7 +/- 17.9 kg that increased to 88.5 +/- 20.3 kg at 52 weeks (p < 0.05). CONCLUSIONS: Subsequent to weight loss from a VLED, meal replacements and Orlistat treatments were both effective in maintaining weight significantly below baseline levels over a 52 week period of time. Meal replacements may be a viable alternative strategy to medications for weight maintenance.

Ingested fat oxidation contributes 8% of 24-h total energy expenditure in moderately obese subjects.

The role of ingested fat in the etiology of obesity is controversial. The aims of this study were to determine the contributions of ingested fat oxidation to: 1) 24-h total energy expenditure (TEE), and 2) substrate oxidation during acute stationary cycle exercises in adult humans. Healthy, moderately obese (n = 18; BMI = 31 +/- 1 kg/m2) subjects (8 men; 10 women) were each studied in a whole-room calorimeter for 24 h. They were fed mixed meals (55, 30, and 15% as energy from carbohydrate, fat and protein, respectively) to maintain energy balance. Each subject performed 1255-kJ cycle exercises at 50% VO2max in the calorimeter. Study test meal fat was labeled with carbon-13 (13C). Ingested fat oxidation was estimated from breath 13CO2 excretion and the subject's chamber CO2 production. Total fat and carbohydrate oxidations were estimated from nonprotein respiratory quotient (NP-RQ) values. Endogenous fat oxidation was estimated as the difference between total fat and ingested fat oxidations. TEE was estimated from gas exchanges; 28 +/- 3% of ingested fat was oxidized and it provided 8 +/- 1% of 24-h TEE. During cycle exercises, ingested fat provided 50% of total fat oxidized and 13.0 +/- 2% of energy expended. Endogenous fat oxidation contributed 10.4 +/- 3% of energy expenditure during cycle exercises. This study extended to 24-h observations of previous studies that lasted 6-9 h on ingested fat oxidation in humans. Understanding the factors that promote ingested fat oxidation could lead to more effective obesity intervention programs.

Beverage consumption patterns in elementary school aged children across a two-year period.

OBJECTIVE: Existing data was reexamined to determine changes in beverage consumption and associations between beverages consumed and BMI Z-score in children (n = 164) across two years. METHODS: Beverages (milk, 100% juice, diet soda or sugar sweetened) and total caloric intake were calculated from a 24-hour diet recall. Height and weight were measured to calculate BMI. Subjects were categorized by BMI Z-score as normal weight, overweight, gained weight and lost weight. Data was collected at baseline and year 2. RESULTS: Significant decreases in milk and increases in diet soda were found over two years in all subjects and normal weight, whereas overweight had a significant increase in diet soda consumption and a decrease in milk consumption that did not reach significance. Change in milk consumption was inversely correlated with sugar-sweetened beverage consumption. Increases in diet soda consumption were significantly greater for overweight and subjects who gained weight as compared to normal weight subjects. Baseline BMI Z-score and year 2 diet soda consumption predicted 83.1% of the variance in year 2 BMI Z-score. CONCLUSION: Shifts in beverage consumption were found in this convenient sample across two years. Diet soda consumption was the only type of beverage associated with year 2 BMI Z-score, and consumption was greater in overweight subjects and subjects who gained weight as compared to normal weight subjects at two years. Additional longitudinal data examining associations between beverage consumption and BMI is needed in children and adolescents, as consumption of regular and diet soda has become more of a social norm.

The role of exercise for weight loss and maintenance.

Exercise provides a means of increasing energy expenditure and may help adjust energy balance for weight loss and maintenance. At least 30 minutes a day of moderate intensity aerobic exercise per day is recommended for weight loss and maintenance but greater amounts appear to increase the magnitude of weight loss and maintenance. Resistance training has recently been shown to have positive effects on body composition but does not typically show significant decreases in weight. Regardless of weight loss, both aerobic exercise and resistance training have been shown to diminish risk factors for cardiovascular disease and diabetes. Since exercise is only effective if sustained, behavioural strategies such as self-monitoring, goal setting, social support, etc. are used to help individuals start and maintain exercise programs and show improved results compared to exercise programs without behavioural strategies. The available evidence indicates that exercise is an important component of weight loss and perhaps the best predictor of weight maintenance.

Number of days, number of subjects, and sources of variation in longitudinal intervention or crossover feeding trials with multiple days of measurement.

Dietary studies are often conducted as longitudinal intervention or crossover trials using multiple days of measurement on each subject during each of several measurement periods, and determining the required numbers of days and subjects is important in designing these studies. Linear mixed statistical models were used to derive equations for precision, statistical power and sample size (number of days and number of subjects) and to obtain estimates of between-subject, period-to-period, and day-to-day variation needed to apply the equations. Two cohorts of an on-going exercise intervention study, and a crossover study of Olestra, each with 14 d of measurement/subject per period, were used to obtain estimates of variability for energy and macronutrient intake. Numerical examples illustrate how the equations for calculating the number of days or number of subjects are applied in typical situations, and sample SAS code is given. It was found that between-subject, period-to-period, and day-to-day variation all contributed significantly to the variation in energy and macronutrient intake. The ratio of period-to-period and day-to-day standard deviations controls the trade-off between the number of days and the number of subjects, and this remained relatively stable across studies and energy and macronutrient intake variables. The greatest gains in precision were seen over the first few measurement days. Greater precision and fewer required days were noted in the study (Olestra) that exerted greater control over the subjects and diets during the feeding protocol.

Multi-point estimation of total energy expenditure: a comparison between zinc-reduction and platinum-equilibration methodologies.

Reducing water to hydrogen gas by zinc or uranium metal for determining D/H ratio is both tedious and time consuming. This has forced most energy metabolism investigators to use the "two-point" technique instead of the "Multi-point" technique for estimating total energy expenditure (TEE). Recently, we purchased a new platinum (Pt)-equilibration system that significantly reduces both time and labor required for D/H ratio determination. In this study, we compared TEE obtained from nine overweight but healthy subjects, estimated using the traditional Zn-reduction method to that obtained from the new Pt-equilibration system. Rate constants, pool spaces, and CO2 production rates obtained from use of the two methodologies were not significantly different. Correlation analysis demonstrated that TEEs estimated using the two methods were significantly correlated (r=0.925, p=0.0001). Sample equilibration time was reduced by 66% compared to those of similar methods. The data demonstrated that the Zn-reduction method could be replaced by the Pt-equilibration method when TEE was estimated using the "Multi-Point" technique. Furthermore, D equilibration time was significantly reduced.

Effects of 16 mo of verified, supervised aerobic exercise on macronutrient intake in overweight men and women: the Midwest Exercise Trial.

BACKGROUND: It is commonly believed that moderate aerobic exercise leads to changes in diet composition, specifically, an increase in carbohydrate intake at the expense of fat intake. OBJECTIVE: The goal was to determine the effects of a supervised, long-term program of exercise on the macronutrient intake of previously sedentary, overweight and moderately obese men and women. DESIGN: Participants (n = 74) were recruited from the university and surrounding communities and were randomly assigned to the exercise or control group. Exercise of moderate intensity was performed for 45 min/d, 5 d/wk, under supervision. Diet intake was ad libitum and was measured for energy and macronutrient composition at baseline and at 5 other occasions across the 16-mo study by use of weighing and measuring techniques. Each measurement consisted of a 2-wk period of direct measurement in the university cafeteria. Food consumption outside the cafeteria during the 2-wk periods (ie, snacks) was measured by multiple-pass 24-h dietary recall procedures. RESULTS: There were no significant differences for men or women between the exercise and control groups from baseline to 16 mo in fat, carbohydrate, or protein intake expressed as grams or as percentages of total energy intake. CONCLUSION: Sixteen months of exercise of moderate intensity does not measurably alter the macronutrient intake of young adults.

Glucose and insulin responses following 16 months of exercise training in overweight adults: the Midwest Exercise Trial.

The current study examined the insulin and glucose response during an oral glucose tolerance test (OGTT) in overweight young adults prior to and following exercise training in the Midwest Exercise Trial (MET). Subjects (N = 66) were randomly assigned to non-exercise control (CON; 16 females, 13 males) or exercise (EX; 22 females, 15 males) groups. EX performed supervised and verified exercise on 3 to 5 days per week in 20- to 45-minute sessions at 60% to 75% of heart rate reserve. OGTTs and assessments for body mass, body composition, and maximal oxygen consumption (Vo(2) max) were performed at baseline, and after 9 and 16 months of training. Blood was collected during a 75-g OGTT and analyzed for glucose and insulin concentrations with the total area under the glucose and insulin curves used in the analysis. The EX males had significant decreases from baseline to 9 months in body mass (94.8 +/- 12.5 to 89.2 +/- 9.8 kg) and percent fat (28.3 +/- 4.8 to 24.2 +/- 3.9) with no further changes at 16 months. CON females had significant increases in body mass (78.2 +/- 6.4 to 81.1 +/- 8.1 kg) and percent fat (36.6 +/- 4.2 to 37.8 +/- 4.7) from baseline to 16 months. Vo(2) max increased significantly from baseline to 9 months in the EX males (3.67 +/- 0.62 to 4.36 +/- 0.55 L/min) and EX females (2.53 +/- 0.32 to 2.99 +/- 0.42 L/min). For glucose area under the curve, there were no significant differences between EX or CON across the 16 months of the study. For insulin area under the curve, there was a significant decrease for male EX from baseline to 9 months (12,535 +/- 6,114 to 8,390 +/- 4,231 microU/L/180 min). We conclude that regular exercise in healthy, previously sedentary overweight adult males leads to improvements in Vo(2) max and weight loss and a reduction in the insulin concentration required to dispose of a set glucose load. In females, improvement in Vo(2) max without weight loss does not lead to improvement in insulin sensitivity.

The validity of the Stanford Seven-Day Physical Activity Recall in young adults.

PURPOSE: To evaluate the criterion validity of the 7-Day Physical Activity Recall (7D-PAR) and factors associated with reporting error, in a sample of moderately overweight, young adult men and women. METHODS: Average total daily energy expenditure (TDEE) and physical activity energy expenditure (PAEE) from the 7D-PAR were compared with the same parameters assessed by doubly labeled water in 17 men, age = 23.9 +/- 3.8 yr, and 29 women, age = 23.3 +/- 4.6 yr, who volunteered to participate in a 16-month supervised aerobic exercise trial. PAEE was estimated from the 7D-PAR and from DLW [0.9 * TDEE -resting metabolic rate (RMR) (indirect calorimetry)]. In addition, peak oxygen uptake and percent body fat were obtained. RESULTS: No significant differences in TDEE (kJ.d-1) were noted between the 7D-PAR (11825 +/- 1779) and DLW (11922 +/- 2516) for the complete sample (N = 46) or for men (7D-PAR = 13198 +/- 1638, DLW = 13885 +/- 2754) or women (7D-PAR = 11018 +/- 1323, DLW = 10771 +/- 1457. The mean PAEE from the 7D-PAR was not different from DLW in the total sample (7D-PAR = 3286 +/- 502, DLW = 3508 +/- 1863) as well as in men (7D-PAR = 3650 +/- 490, DLW = 3989 +/- 2461) and women (3073 +/- 377, DLW = 3223 +/- 1360). In a regression model, PAEE, peak oxygen uptake, gender and percent fat accounted for 86% of the reporting error in total daily energy expenditure when using the 7D-PAR. CONCLUSION: The 7D-PAR provided a reasonable estimate of both the mean TDEE and PAEE in this sample; however, estimates of energy expenditure on an individual basis using the PAR were subject to considerable error.

Effects of a 16-month randomized controlled exercise trial on body weight and composition in young, overweight men and women: the Midwest Exercise Trial.

BACKGROUND: In light of the current obesity epidemic, treatment models are needed that can prevent weight gain or provide weight loss. We examined the long-term effects of a supervised program of moderate-intensity exercise on body weight and composition in previously sedentary, overweight and moderately obese men and women. We hypothesized that a 16-month program of verified exercise would prevent weight gain or provide weight loss in the exercise group compared with controls. METHODS: This was a randomized controlled efficacy trial. Participants were recruited from 2 midwestern universities and their surrounding communities. One hundred thirty-one participants were randomized to exercise or control groups, and 74 completed the intervention and all laboratory testing. Exercise was supervised, and the level of energy expenditure of exercise was measured. Controls remained sedentary. All participants maintained ad libitum diets. RESULTS: Exercise prevented weight gain in women and produced weight loss in men. Men in the exercise group had significant mean +/- SD decreases in weight (5.2 +/- 4.7 kg), body mass index (calculated as weight in kilograms divided by the square of height in meters) (1.6 +/- 1.4), and fat mass (4.9 +/- 4.4 kg) compared with controls. Women in the exercise group maintained baseline weight, body mass index, and fat mass, and controls showed significant mean +/- SD increases in body mass index (1.1 +/- 2.0), weight (2.9 +/- 5.5 kg), and fat mass (2.1 +/- 4.8 kg) at 16 months. No significant changes occurred in fat-free mass in either men or women; however, both had significantly reduced visceral fat. CONCLUSIONS: Moderate-intensity exercise sustained for 16 months is effective for weight management in young adults.

Validation of energy intake measurements determined from observer-recorded food records and recall methods compared with the doubly labeled water method in overweight and obese individuals.

BACKGROUND: Measurements of dietary intake in obese and overweight populations are often inaccurate because food intakes are underestimated. OBJECTIVE: The purpose of this study was to evaluate the validity of the combined use of observer-recorded weighed-food records and 24-h snack recalls in estimating energy intakes in overweight and obese individuals. DESIGN: Subjects were 32 healthy women and 22 healthy men with mean body mass indexes (in kg/m(2)) of 29.5 and 30.3, respectively. Energy intake (EI) was measured over 2 wk in a university cafeteria. No restrictions were made on meal frequency or EI. To document food consumed outside the cafeteria, 24-h snack recalls were conducted before meals. Energy expenditure (EE) was measured with the doubly labeled water (DLW) method (EE(DLW)). Energy balance was determined by measuring body weight at the beginning and end of the 2-wk period. RESULTS: The mean EI in the women (10.40 +/- 1.94 MJ/d) and men (14.37 +/- 3.21 MJ/d) was not significantly lower than the EE(DLW) in the women (10.86 +/- 1.76 MJ/d) and men (14.14 +/- 2.83 MJ/d). The mean EI represented 96.9 +/- 17.0% and 103 +/- 18.9% of the measured EE for women and men, respectively. There were no significant changes in weight in the group as a whole or by sex at the end of the testing period; the men lost 0.23 +/- 1.58 kg and the women lost 0.25 +/- 1.09 kg. CONCLUSION: The combination of observer-recorded food records and 24-h snack recalls is a valid method for measuring EI in overweight and obese individuals.

Changes in Lower Leg Anterior Compartment Pressure Before, During, and After Creatine Supplementation.

OBJECTIVE: To determine if 35 days of creatine supplementation (Cr) followed by 28 days of no supplementation altered lower leg anterior compartment pressure (ACP) at rest and after exercise. DESIGN AND SETTING: Subjects were divided into 2 treatment groups: (1) high dose (0.3 g Cr.kg body mass(-1).d(-1) for 7 days followed by 0.03 g Cr.kg body mass(-1).d(-1) for 28 days), or (2) low dose (0.03 g Cr.kg body mass(-1).d(-1) for 35 days). After 35 days, supplementation was terminated, and no Cr was ingested for 28 days. SUBJECTS: Sixteen physically active, healthy, college-aged males (O(2)max = 47.6 +/- 5.1 mL.kg(-1).min(-1)). MEASUREMENTS: At baseline, 7 days and 35 days of supplementation, and 28 days postsupplementation, ACP was measured preexercise and immediately, 1, 5, 10, and 15 minutes postexercise after a treadmill run at 80% O(2)max. RESULTS: For ACP, there was no significant group-by-time interaction, but there was a significant time effect for group when the data were combined. ACP was significantly increased at preexercise, immediately postexercise, and 1, 5, and 10 minutes from baseline to 7 days. ACP remained significantly elevated from baseline at 35 days immediately postexercise and 1 minute postexercise. After 28 days of no supplementation, ACP began to return to presupplementation levels, with only the 1-minute postexercise measurement significantly elevated from baseline. CONCLUSIONS: Creatine supplementation increased ACP at rest and after exercise, and ACP began to return to normal after 28 days of no supplementation.