Determining optimal approaches for weight maintenance: a randomized controlled trial.

BACKGROUND: Weight regain often occurs after weight loss in overweight individuals. We aimed to compare the effectiveness of 2 support programs and 2 diets of different macronutrient compositions intended to facilitate long-term weight maintenance. METHODS: Using a 2 x 2 factorial design, we randomly assigned 200 women who had lost 5% or more of their initial body weight to an intensive support program (implemented by nutrition and activity specialists) or to an inexpensive nurse-led program (involving "weigh-ins" and encouragement) that included advice about high-carbohydrate diets or relatively high-monounsaturated-fat diets. RESULTS: In total, 174 (87%) participants were followed-up for 2 years. The average weight loss (about 2 kg) did not differ between those in the support programs (0.1 kg, 95% confidence interval [CI] -1.8 to 1.9, p = 0.95) or diets (0.7 kg, 95% CI -1.1 to 2.4, p = 0.46). Total and low-density lipoprotein (LDL) cholesterol levels were significantly higher among those on the high-monounsaturated-fat diet (total cholesterol: 0.17 mmol/L, 95% CI 0.01 to 0.33; p = 0.040; LDL cholesterol: 0.16 mmol/L, 95% CI 0.01 to 0.31; p = 0.039) than among those on the high-carbohydrate diet. Those on the high-monounsaturated-fat diet also had significantly higher intakes of total fat (5% total energy, 95% CI 3% to 6%, p < 0.001) and saturated fat (2% total energy, 95% CI 1% to 2%, p < 0.001). All of the other clinical and laboratory measures were similar among those in the support programs and diets. INTERPRETATION: A relatively inexpensive program involving nurse support is as effective as a more resource-intensive program for weight maintenance over a 2-year period. Diets of different macronutrient composition produced comparable beneficial effects in terms of weight loss maintenance.

Body mass index status is effective in identifying metabolic syndrome components and insulin resistance in Pacific Island teenagers living in New Zealand.

Although adults of Pacific ethnicity living in New Zealand have more than double the prevalence of diabetes and cardiovascular disease than the general population, little is known regarding the presence of risk factors for these disorders among young Pacific Islanders. The study aim was to examine relationships between body composition, glucose and lipid metabolism, and components of the metabolic syndrome (MS) in a community sample of Pacific Island (PI) teenagers living in Dunedin. Anthropometry, body composition (dual-energy x-ray absorptiometry), glucose and lipid metabolism, insulin resistance (homeostasis model assessment [HOMA2], McAuley index), and components of MS were assessed in 80 PI teenagers (aged 15-18 years). Results showed that 6 participants had full MS, 2 had high fasting blood glucose values (>7.0 mmol/L), 55 had high adiposity, and 21 had insulin resistance. Assessment of the components of MS by body mass index (BMI) status showed that obese participants (n = 29) had a high prevalence (86.2% had one or more component), whereas only 10.5% of those with healthy BMI status (n = 19) had any MS component. Elevated fat mass had substantial effects on fasting insulin values, HOMA2, and the McAuley index because in data adjusted for age, sex, and lean mass, a 10% greater fat mass was associated with a 4.7% increase in fasting insulin, a 5.3% rise in HOMA2, and a 2.3% decrease in the McAuley index. Our results suggest that the antecedents of cardiovascular disease and type 2 diabetes mellitus occur frequently in young Pacific Islanders having high adiposity. We conclude that community studies of PI adolescents should focus on assessing risk factors whenever BMI values are high.

Monte Carlo analysis of a new model-based method for insulin sensitivity testing.

Insulin resistance (IR), or low insulin sensitivity, is a major risk factor in the pathogenesis of type 2 diabetes and cardiovascular disease. A simple, high resolution assessment of IR would enable earlier diagnosis and more accurate monitoring of intervention effects. Current assessments are either too intensive for clinical settings (Euglycaemic Clamp, IVGTT) or have too low resolution (HOMA, fasting glucose/insulin). Based on high correlation of a model-based measure of insulin sensitivity and the clamp, a novel, clinically useful test protocol is designed with: physiological dosing, short duration (<1 h), simple protocol, low cost and high repeatability. Accuracy and repeatability are assessed with Monte Carlo analysis on a virtual clamp cohort (N=146). Insulin sensitivity as measured by this test has a coefficient of variation (CV) of CV(SI)=4.5% (90% CI: 3.8-5.7%), slightly higher than clamp ISI (CV(ISI)=3.3% (90% CI: 3.0-4.0%)) and significantly lower than HOMA (CV(HOMA)=10.0% (90% CI: 9.1-10.8%)). Correlation to glucose and unit normalised ISI is r=0.98 (90% CI: 0.97-0.98). The proposed protocol is simple, cost effective, repeatable and highly correlated to the gold-standard clamp.

APPLE Project: 2-y findings of a community-based obesity prevention program in primary school age children.

BACKGROUND: Developing effective strategies for obesity prevention in children is urgently required. OBJECTIVE: We determined the effectiveness of a 2-y controlled community-based intervention to prevent excessive weight gain in 5-12-y-old children by enhancing opportunities for healthy eating and noncurricular physical activity. DESIGN: Children (n = 730) from 4 intervention and 3 control schools underwent measurements of height, weight, waist circumference, blood pressure, diet, and physical activity at baseline and at 1 and 2 y. Intervention components included nutrition education that targeted reductions in sweetened drinks and increased fruit and vegetable intake and activity coordinators who managed an activity program that focused on noncurricular lifestyle-based activities (eg, community walks). RESULTS: Body mass index (BMI; in kg/m2) z score was significantly lower in intervention children than in control children by a mean of 0.09 (95% CI: 0.01, 0.18) after 1 y and 0.26 (95% CI: 0.21, 0.32) at 2 y, but the prevalence of overweight did not differ. Waist circumference was significantly lower at 2 y (-1 cm), and systolic blood pressure was reduced at 1 y (-2.9 mm Hg). An interaction existed between intervention group and overweight status (P = 0.029), such that mean BMI z score was reduced in normal-weight (-0.29; 95% CI: -0.38, -0.21) but not overweight (-0.02; 95% CI: -0.16, 0.12) intervention children relative to controls. Intervention children consumed fewer carbonated beverages (67% of control intake; P = 0.04) and fruit juice or drinks (70%; P = 0.03) and more fruit (0.8 servings/3 d; P < 0.01). CONCLUSION: A relatively simple approach, providing activity coordinators and basic nutrition education in schools, significantly reduces the rate of excessive weight gain in children, although this may be limited to those not initially overweight. This trial was registered at Australian Clinical Trials Registry as #12605000578606.

Transient and steady-state euglycemic clamp validation of a model for glycemic control and insulin sensitivity testing.

BACKGROUND: There is an urgent need for a simple and accurate measure of insulin sensitivity to diagnose insulin resistance in the general population and quantify changes due to clinical intervention. A new physiological control model of glucose and insulin metabolism is validated with the euglycemic-hyperinsulinemic clamp during steady and transient states. METHODS: The data consist of n = 60 (15 lean, 15 overweight, 15 obese, and 15 morbidly obese) euglycemic-hyperinsulinemic clamp trials performed on normoglycemic insulin-resistant individuals. The glucose and insulin model is fitted using an integral-based method. Correlations between clamp-derived insulin sensitivity index (ISI) and the model's insulin sensitivity parameter (SI) are obtained during steady and transient states. Results are compared with log-homeostasis model assessment (HOMA), a widely used fasting surrogate for insulin sensitivity. RESULTS: Correlation between model-based insulin sensitivity, SI, and ISIG (ISI normalized by steady-state glucose) is r = 0.99 (n = 60) at steady state and r = 0.97 at transient state, respectively. Correlations did not significantly change across subgroups, with narrow 95% confidence intervals. Log-HOMA correlations are r=-0.72 to SI and r=-0.71 to ISIG for the overall population but are significantly lower in the subgroups, with wide 95% confidence intervals. CONCLUSIONS: The model-based insulin sensitivity parameter, SI, highly correlates to ISIG in all subgroups, even when only considering a transient state. The high correlation of SI offers the potential for a short, simple yet highly correlated, model-based assessment of insulin sensitivity that is not currently available.

Insulin resistance and impaired glucose metabolism in a predominantly Maori community.

We sought to identify lifestyle behaviours which influence risk of impaired glucose metabolism, IGM (newly diagnosed type 2 diabetes, impaired glucose tolerance [IGT] or impaired fasting glycemia [IFG]) or insulin resistance (IR) in a predominantly Maori community, and applied the McAuley formula to determine whether it predicts high risk individuals amongst this community. Three hundred and seventy one participants completed a lifestyle and dietary behaviour questionnaire and oral glucose tolerance test. Clinical variables, microalbuminuria, fasting glucose, insulin and lipids were measured. Diabetes, IFG and IGT were defined according to WHO criteria. IR was defined using the McAuley formula. Those with IGM and those with IR showed similar risk factor attributes. Odds ratios (95% CI) for development of IGM and IR were 0.43 (0.21-0.88) and 0.51 (0.33-0.80), respectively, for regular physical activity, and 0.55 (0.26-1.15) and 0.59 (0.37-0.96), respectively, for two or more dietary behaviours characterized by a high intake of fibre. Regular physical activity and a diet characterized by a high intake of dietary fibre were found to reduce risk of newly diagnosed IGM or IR. The McAuley formula appears to predict high-risk individuals in a predominantly Maori population as it does in European populations.

Exercise training is not associated with improved levels of C-reactive protein or adiponectin.

The purpose of this study was to determine the effect of exercise training on the levels of C-reactive protein (CRP) and adiponectin, and to assess whether exercise-induced changes in insulin resistance could be explained in part by changes in these inflammation markers. Study participants included 51 middle-aged (45.3+/-8.3 years; mean+/-SD), overweight (33.7+/-4.8 BMI), insulin-resistant, nondiabetic individuals. Subjects had their insulin sensitivity, body fat, CRP, and adiponectin levels measured, and their predicted maximal fitness calculated before and after 16 weeks of moderate, intense, or no exercise training. Modest improvements in fitness, body composition, and insulin sensitivity were observed, but these changes were not associated with decreased CRP or increased adiponectin levels, even when subjects were stratified by their change in fitness or obesity. Regression analysis demonstrated that the change in percentage of body fat was significantly related to changes in insulin sensitivity, whereas changes in VO2 MAX, CRP, and adiponectin were not. Participation in moderate to intense exercise was not associated with improved measures of chronic inflammation markers, as measured by CRP and adiponectin. Moreover, improvements in insulin sensitivity resulting from exercise or modest weight loss did not appear to be related to changes in these markers.

Intensive lifestyle changes are necessary to improve insulin sensitivity: a randomized controlled trial.

OBJECTIVE: The extent to which lifestyle must be altered to improve insulin sensitivity has not been established. This study compares the effect on insulin sensitivity of current dietary and exercise recommendations with a more intensive intervention in normoglycemic insulin-resistant individuals. RESEARCH DESIGN AND METHODS: Seventy-nine normoglycemic insulin-resistant (determined by the euglycemic insulin clamp) men and women were randomized to either a control group or one of two combined dietary and exercise programs. One group (modest level) was based on current recommendations and the other on a more intensive dietary and exercise program. Insulin sensitivity was measured using a euglycemic insulin clamp, body composition was measured using dual-energy X-ray absorptiometry, and anthropometry and aerobic fitness were assessed before and after a 4-month intervention period. Four-day dietary intakes were recorded, and fasting glucose, insulin, and lipids were measured. RESULTS: Only the intensive group showed a significant improvement in insulin sensitivity (23% increase, P=0.006 vs. 9% in the modest group, P=0.23). This was associated with a significant improvement in aerobic fitness (11% increase in the intensive group, P=0.02 vs. 1% in the modest group, P=0.94) and a greater fiber intake, but no difference in reported total or saturated dietary fat. CONCLUSIONS: Current clinical dietary and exercise recommendations, even when vigorously implemented, did not significantly improve insulin sensitivity; however, a more intensive program did. Improved aerobic fitness appeared to be the major difference between the two intervention groups, although weight loss and diet composition may have also played an important role in determining insulin sensitivity.

Clinical validation of the quick dynamic insulin sensitivity test.

The quick dynamic insulin sensitivity test (DISTq) can yield an insulin sensitivity result immediately after a 30-min clinical protocol. The test uses intravenous boluses of 10 g glucose and 1 U insulin at t = 1 and 11 min, respectively, and measures glucose levels in samples taken at t = 0, 10, 20, and 30 min. The low clinical cost of the protocol is enabled via robust model formulation and a series of population-derived relationships that estimate insulin pharmacokinetics as a function of insulin sensitivity (SI). Fifty individuals underwent the gold standard euglycaemic clamp (EIC) and DISTq within an eight-day period. SI values from the EIC and two DISTq variants (four-sample DISTq and two-sample DISTq30) were compared with correlation, Bland-Altman and receiver operator curve analyses. DISTq and DISTq30 correlated well with the EIC [R = 0.76 and 0.75, and receiver operator curve c-index = 0.84 and 0.85, respectively]. The median differences between EIC and DISTq/DISTq30 SI values were 13% and 22%, respectively. The DISTq estimation method predicted individual insulin responses without specific insulin assays with relative accuracy and thus high equivalence to EIC SI values was achieved. DISTq produced very inexpensive, relatively accurate immediate results, and can thus enable a number of applications that are impossible with established SI tests.

A spectrum of dynamic insulin sensitivity test protocols.

BACKGROUND: Numerous tests have been developed to estimate insulin sensitivity (SI). However, most of the established tests are either too expensive for widespread application or do not yield reliable results. The dynamic insulin sensitivity and secretion test (DISST) uses assays of glucose, insulin, and C-peptide from nine samples to quantify SI and endogenous insulin secretion (UN) at a comparatively low cost. The quick dynamic insulin sensitivity test has shown that the DISST SI values are robust to significant assay omissions. METHODS: Eight DISST-based variations of the nine-sample assay regimen are proposed to investigate the effects of assay omission within the DISST-based framework. SI and UN were identified using the fully-sampled DISST and data from 218 nine-sample tests undertaken in 74 female individuals with elevated diabetes risk. This same data was then used with appropriate assay omissions to identify SI and UN with the eight DISST-based assay variations. RESULTS: Median intraprocedure proportional difference between SI values from fully-sampled DISST and the DISST-based variants was in the range of -17.9 to 7.8%. Correlations were in the range of r = 0.71 to 0.92 with the highest correlations between variants with the greatest commonality with the nine-sample DISST. Metrics of UN correlated relatively well between tests when C-peptide was assayed (r = 0.72 to 1) but were sometimes not well estimated when samples were not assayed for C-peptide (r = -0.14 to 0.75). CONCLUSIONS: The DISST-based spectrum offers a series of tests with very distinct compromises of information yield, accuracy, assay cost, and clinical intensity. Thus, the spectrum of tests has the potential to enable researchers to better allocate funds by selecting an optimal test configuration for their particular application.

The dynamic insulin sensitivity and secretion test--a novel measure of insulin sensitivity.

The objective was to validate the methodology for the dynamic insulin sensitivity and secretion test (DISST) and to demonstrate its potential in clinical and research settings. One hundred twenty-three men and women had routine clinical and biochemical measurements, an oral glucose tolerance test, and a DISST. For the DISST, participants were cannulated for blood sampling and bolus administration. Blood samples were drawn at t = 0, 10, 15, 25, and 35 minutes for measurement of glucose, insulin, and C-peptide. A 10-g bolus of intravenous glucose at t = 5 minutes and 1 U of intravenous insulin immediately after the t = 15 minute sample were given. Fifty participants also had a hyperinsulinemic-euglycemic clamp. Relationships between DISST insulin sensitivity (SI) and the clamp, and both DISST SI and secretion and other metabolic variables were measured. A Bland-Altman plot showed little bias in the comparison of DISST with the clamp, with DISST underestimating the glucose clamp by 0.1·10(-2)·mg·L·kg(-1)·min(-1)·pmol(-1) (90% confidence interval, -0.2 to 0). The correlation between SI as measured by DISST and the clamp was 0.82; the c unit for the receiver operating characteristic curve analysis for the 2 tests was 0.96. Metabolic variables showed significant correlations with DISST SI and the second phase of insulin release. The DISST also appears able to distinguish different insulin secretion patterns in individuals with identical SI values. The DISST is a simple, dynamic test that compares favorably with the clamp in assessing SI and allows simultaneous assessment of insulin secretion. The DISST has the potential to provide even more information about the pathophysiology of diabetes than more complicated tests.

Economic evaluation of a community-based obesity prevention program in children: the APPLE project.

Effective strategies are urgently required to reduce the prevalence of obesity during growth. Determining which strategies are most successful should also include analysis of their relative costs. To date, few obesity prevention studies in children have reported data concerning cost-effectiveness. The aim of this study was to assess the costs and health benefits of implementing the APPLE (A Pilot Program for Lifestyle and Exercise) project, a 2-year controlled community-based obesity prevention initiative utilizing activity coordinators (ACs) in schools and nutrition promotion in New Zealand children (5-12 years). The marginal costs of the project in 2006 prices were estimated and compared with the kilograms (kg) of weight-gain prevented for children in the intervention relative to the control arm. The children's health-related quality of life (HRQoL) was also measured using the Health Utilities Index (HUI). The total project cost was NZ$357,490, or NZ$1,281 per intervention child for 2 years (NZ$1 = US$0.67 = UK pound 0.35 = EUR euro 0.52). Weight z-score was reduced by 0.18 (0.13, 0.22) units at 2 years and 0.17 (0.11, 0.23) units at 4 years in intervention relative to control children. Mean HUI values did not differ between intervention and control participants. The reduction in weight z-score observed is equivalent to 2.0 kg of weight-gain prevented at 15 years of age. The relatively simple intervention approach employed by the APPLE project was successful in significantly reducing the rate of excessive weight gain in children, with implementation costs of NZ$664-1,708 per kg of weight-gain prevented over 4 years.

A three-compartment model of the C-peptide-insulin dynamic during the DIST test.

Dynamic insulin sensitivity (SI) tests often utilise model-based parameter estimation. This research analyses the impact of expanding the typically used two-compartment model of insulin and C-peptide kinetics to incorporate a hepatic third compartment. The proposed model requires only four C-peptide assays to simulate endogenous insulin production (uen), greatly reducing the cost and clinical burden. Sixteen subjects participated in 46 dynamic insulin sensitivity tests (DIST). Population kinetic parameters are identified for the new compartment. Results are assessed by model error versus measured data and repeatability of the identified SI. The median C-peptide error was 0% (IQR: -7.3, 6.7)%. Median insulin error was 7% (IQR: -28.7, 6.3)%. Strong correlation (r=0.92) existed between the SI values of the new model and those from the original two-compartment model. Repeatability in SI was similar between models (new model inter/intra-dose variability 3.6/12.3% original model -8.5/11.3%). When frequent C-peptide samples may be available, the added hepatic compartment does not offer significant diagnostic, repeatability improvement over the two-compartment model. However, a novel and successful three-compartment modelling strategy was developed which provided accurate estimation of endogenous insulin production and the subsequent SI identification from sparse C-peptide data.

The identification of insulin saturation effects during the dynamic insulin sensitivity test.

BACKGROUND: Many insulin sensitivity (SI) tests identify a sensitivity metric that is proportional to the total available insulin and measured glucose disposal despite general acceptance that insulin action is saturable. Accounting for insulin action saturation may aid inter-participant and/or inter-test comparisons of insulin efficiency, and model-based glycaemic regulation. METHOD: Eighteen subjects participated in 46 dynamic insulin sensitivity tests (DIST, low-dose 40-50 minute insulin-modified IVGTT). The data was used to identify and compare SI metrics from three models: a proportional model (SI(L)), a saturable model (SI(S )and Q50) and a model similar to the Minimal Model (SG and SI(G)). The three models are compared using inter-trial parameter repeatability, and fit to data. RESULTS: The single variable proportional model produced the metric with least intra-subject variation: 13.8% vs 40.1%/55.6%, (SI(S)/I50) for the saturable model and 15.8%/88.2% (SI(G)/SG) for the third model. The average plasma insulin concentration at half maximum action (I50) was 139.3 mU·L⁻¹, which is comparable to studies which use more robust stepped EIC protocols. CONCLUSIONS: The saturation model and method presented enables a reasonable estimation of an overall patient-specific saturation threshold, which is a unique result for a test of such low dose and duration. The detection of previously published population trends and significant bias above noise suggests that the model and method successfully detects actual saturation signals. Furthermore, the saturation model allowed closer fits to the clinical data than the other models, and the saturation parameter showed a moderate distinction between NGT and IFG-T2DM subgroups. However, the proposed model did not provide metrics of sufficient resolution to enable confidence in the method for either SI metric comparisons across dynamic tests or for glycamic control.

Design and clinical pilot testing of the model-based dynamic insulin sensitivity and secretion test (DISST).

BACKGROUND: Insulin resistance is a significant risk factor in the pathogenesis of type 2 diabetes. This article presents pilot study results of the dynamic insulin sensitivity and secretion test (DISST), a high-resolution, low-intensity test to diagnose insulin sensitivity (IS) and characterize pancreatic insulin secretion in response to a (small) glucose challenge. This pilot study examines the effect of glucose and insulin dose on the DISST, and tests its repeatability. METHODS: DISST tests were performed on 16 subjects randomly allocated to low (5 g glucose, 0.5 U insulin), medium (10 g glucose, 1 U insulin) and high dose (20 g glucose, 2 U insulin) protocols. Two or three tests were performed on each subject a few days apart. RESULTS: Average variability in IS between low and medium dose was 10.3% (p=.50) and between medium and high dose 6.0% (p=.87). Geometric mean variability between tests was 6.0% (multiplicative standard deviation (MSD) 4.9%). Geometric mean variability in first phase endogenous insulin response was 6.8% (MSD 2.2%). Results were most consistent in subjects with low IS. CONCLUSIONS: These findings suggest that DISST may be an easily performed dynamic test to quantify IS with high resolution, especially among those with reduced IS.

Body mass index and waist circumference cutoffs to define obesity in indigenous New Zealanders.

BACKGROUND: The suggestion that body mass index (BMI) cutoffs to define obesity should differ in persons of Polynesian descent compared with Europeans is based principally on the observation that persons of Polynesian descent have a relatively higher proportion of lean body mass for a given BMI. OBJECTIVES: The objectives were to determine whether the relation between BMI, waist circumference, and metabolic comorbidity differs in the 2 major ethnic groups in New Zealand and to ascertain whether ethnicity-specific BMI and waist circumference cutoffs for obesity are justified for Maori (indigenous New Zealanders). DESIGN: Subjects included a convenience sample of 1539 men and women aged 17-82 y (47% Maori, 53% white) with measures of BMI, waist circumference, blood pressure, fasting insulin, glucose, and lipids. The sensitivity and specificity of BMI (in kg/m(2); 30 and 32), waist circumference (80 and 88 cm in women, 94 and 102 cm in men), and waist-to-height ratio (WHtR; > or =0.6) in relation to insulin sensitivity, insulin resistance, and the metabolic syndrome were determined. Receiver operating characteristic curves and areas under the curve (AUCs) were also calculated. RESULTS: No ethnic or sex differences between AUCs were observed for BMI, waist circumference, or WHtR, which showed that these anthropometric measures perform similarly in Maori and European men and women and correctly discriminate between those with and without insulin resistance or the metabolic syndrome 79-87% of the time. Any increase in specificity from a higher BMI cutoff of 32 in Maori was offset by appreciable reductions in sensitivity. CONCLUSION: These findings argue against having different BMI or waist circumference cutoffs for people of Polynesian descent.

Sustainability of lifestyle changes following an intensive lifestyle intervention in insulin resistant adults: Follow-up at 2-years.

The objective of this study was to determine whether overweight insulin resistant individuals who lost weight and improved cardiovascular risk factors during a 4-month lifestyle intervention could sustain these lifestyle changes in the long-term. Seventy-nine insulin resistant adults were randomised to a control group or either a modest or intensive lifestyle intervention group for 4-months. Thereafter the two intervention groups were combined and all participants were followed-up at 8, 12 and 24 months. Anthropometry, blood pressure, fasting glucose, lipids, insulin and aerobic fitness were measured and dietary intake was assessed. An interview was conducted to determine factors which participants perceived facilitated or hindered maintenance of healthy lifestyle habits. Seventy-two (91.1%), sixty-nine (87.3%) and sixty-two (78.5%) participants were retained at 8, 12 and 24-month respectively. At 4-months the adjusted difference in weight between the modest and control groups was -3.4 kg (95% CI -5.4, -1.3) p=0.002 and intensive and control groups was -4.7 kg (-6.9, -2.4) p=0.0001 respectively. At 2-years there were no significant differences for weight when the initial 3 groups were compared or when the combined intervention group was compared with the control group. At 2-years, 64% of participants reported that more frequent follow-up would have helped them to maintain healthy lifestyle habits. Even intensive counselling for 4-months with 4-monthly and then yearly monitoring were not enough for maintaining lifestyle changes sufficient to sustain weight loss. More frequent monitoring for an indefinite period was perceived by two-thirds of participants as necessary for them to maintain their initial lifestyle changes.

Two-year follow-up of an obesity prevention initiative in children: the APPLE project.

BACKGROUND: In a 2-y intervention targeting increased physical activity and healthy eating in primary school children, the adjusted body mass index (BMI) z score was 0.26 units (95% CI: 0.21, 0.32) lower in intervention than in control children. Few obesity prevention initiatives in children have undertaken follow-up analyses. OBJECTIVE: The objective was to determine whether differences in BMI persisted approximately 2 y after the cessation of the intervention. DESIGN: All children who had at least one measurement of height and weight at any time during the study (baseline and years 1 or 2) were invited to participate in follow-up measurements (height and weight). RESULTS: Five hundred fifty-four of 727 eligible children (76%) participated. Children who refused to participate (n = 14) or had moved from the study area (n = 159) did not differ from the remaining participants in baseline age, sex, or BMI. The mean BMI z score (and 95% CI) remained significantly lower in intervention children at follow-up in the whole group (n = 554; -0.17; -0.25, -0.08) and in the group who underwent at least 1 (n = 389; -0.19; -0.24, -0.13) or 2 (n = 256; -0.21; -0.29, -0.14) full years of intervention. Intervention children were less likely to be overweight, but only in those who were present for the full intervention (n = 256; RR: 0.81; 95% CI: 0.69, 0.94). CONCLUSION: Despite the main intervention initiative (school-based activity coordinators charged with the responsibility of enhancing physical activity and promoting healthy eating) being discontinued at the end of the intervention, continued benefits to BMI remained apparent in intervention children approximately 2 y later.

Reducing weight gain in children through enhancing physical activity and nutrition: the APPLE project.

OBJECTIVE: Community-based lifestyle intervention may offer the best means of reducing the global epidemic of childhood obesity and its consequences, yet few successful interventions have been reported. The objective was to determine whether increasing extra-curricular levels of activity could reduce weight gain in children. METHODS: A controlled intervention study was conducted using standardised methods to assess outcomes. Two comparable relatively rural communities in Otago, New Zealand formed intervention and control settings. Height, weight, waist circumference and participation in physical activity (by accelerometry) were measured at baseline and at 1 year in 384 children aged 5 to 12 years representing the majority of children in this age group in intervention and control communities. Community Activity Co-ordinators were employed at each school in the intervention area. Their brief was to widen exposure to activity and engage children not interested in traditional sporting activities by encouraging lifestyle-based activities (e.g. walking) and non-traditional sports (e.g. golf and taekwondo) during extra-curricular time at school, after school and during vacations. Simple dietary advice was offered and the wider community was encouraged to participate. RESULTS: Average accelerometry counts at 1 year were 28% (95% CI: 11 to 47%) higher in intervention compared with control children after adjusting for age, sex, baseline values and school. Intervention children spent less time in sedentary activity (ratio 0.91, p = 0.007) and more time in moderate (1.07, p = 0.001) and moderate/vigorous (1.10, p = 0.01) activity. Adjusted mean BMI Z-score was lower in intervention relative to control children by -0.12 units (95% CI: -0.22 to -0.02). CONCLUSION: . An intervention designed to maximise opportunities for physical activity during extra-curricular time at school and during leisure time through the provision of community-based Activity Co-ordinators significantly increased participation in physical activity and slowed unhealthy weight gain in primary school-aged children.