Changes in BMI and waist circumference in Scottish adults: use of repeated cross-sectional surveys to explore multiple age groups and birth-cohorts

Low-Volume High-Intensity Interval Training (HIIT) versus Moderate-Intensity Continuous Training on Body Composition, Cardiometabolic Profile and Physical Capacity in Older Women

OBJECTIVES

To compare the effect of low-volume HIIT to moderate-intensity aerobic training (MICT) on fat mass, cardiometabolic profile and physical capacity and confirm its feasibility in older women.

METHODS

Inactive older women (60-75 years) were randomly assigned to 8 weeks of either HIIT (75 min/week; n=9) or MICT (150 min/week; n=9). Body composition, fasting metabolic profile, cardiovascular risk (Framingham score), and physical capacity (senior fitness test, VO2peak) were assessed before and after the intervention. Feasibility was evaluated with completion rate (training compliance; dropout rate) and affective response (Feeling scale; pre- and post-exercise).

RESULTS

Total cholesterol, non-HDL-C levels and the Framingham risk score decreased in both groups (all p≤0.03). Although VO2peak remained unchanged, the 6MWT distance increased (p<0.0001), irrespective of the group. Completion rate and affective responses were not different between groups (all p≥0.38).

CONCLUSION

A short-term HIIT program is feasible and provides as much benefits as MICT in older women.

Sarcopenic obesity can be negatively associated with active physical activity and adequate intake of some nutrients in Korean elderly: Findings from the Korea National Health and Nutrition Examination Survey (2008-2011)

BACKGROUND/OBJECTIVES

The aim of this study was to analyze the factors related to sarcopenic obesity among the elderly in South Korea.

SUBJECTS/METHODS

A total of 3,367 elderly (≥ 65 years) from the Korea National Health and Nutrition Examination Survey (2008–2011) were included in this analysis. The subjects were assessed to determine their sarcopenia and obesity status. Sarcopenia was assessed by determining their appendicular skeletal muscle mass (ASM). Obesity was defined by the waist circumference. An association of sarcopenic obesity and the related factors was analyzed using multiple logistic regression models.

RESULTS

The risk of sarcopenic obesity of the subjects was decreased by active physical activity. After adjusting for age, smoking, and alcohol consumption, the risk of sarcopenic obesity in men of the highest level group (Q4) decreased by 45% (OR = 0.550, 95% CI = 0.334–0.905, P trend 0.018) compared to that in the reference group (Q1). Among the women, the risk of sarcopenic obesity in the Q3 and Q4 groups decreased by 29.0% (OR = 0.710, 95% CI = 0.512–0,984) and 56.7% (OR = 0.433, 95% CI = 0.281–0.668), respectively, compared to that in the Q1 group (P trend < 0.001). The mean daily energy intake was higher in the non-sarcopenia group than in the sarcopenia group. The risk of sarcopenic obesity in subjects not meeting the recommended intakes of energy, riboflavin, and vitamin C increased significantly by 25.4%, and 36.6%, and 32.6%, respectively, compared to that in the subjects meeting the recommended nutrient intake.

CONCLUSION

Active physical activity as well as an adequate intake of energy and some vitamins might be negatively associated with the development of sarcopenia and sarcopenic obesity in the elderly.

Association of Obesity and Frailty in Older Adults: NHANES 1999-2004

OBJECTIVES

Body composition changes with aging can increase rates of obesity, frailty and impact function. Measuring adiposity using body fat (%BF) or central adiposity using waist circumference (WC) have greater diagnostic accuracy than traditional measures such as body mass index (BMI).

DESIGN

This is an observational study.

SETTING

This study focused on older community-dwelling participants.

PARTICIPANTS

We identified individuals age ≥ 60 years old using the 1999-2004 cross-sectional National Health and Nutrition Survey (NHANES).

INTERVENTION

The primary analysis evaluated the association between frailty and %BF or WC. Frailty was the primary predictor (robust=referent) and %BF and WC were considered continuous outcomes. Multiple imputation analyses accounted for missing characteristics.

MEASUREMENT

Dual energy x-ray absorptiometry was used to assess %BF and WC was objectively measured. Frailty was defined using an adapted version of Fried's criteria that was self-reported: (low BMI<18.5kg/m2; slow walking speed [<0.8m/s]; weakness [unable to lift 10lbs]; exhaustion [difficulty walking between rooms on same floor] and low physical activity [compared to others]). Robust, pre-frail and frail persons met zero, 1 or 2, and ≥3 criteria, respectively.

RESULTS

Of the 4,984 participants, the mean age was 71.1±0.2 (SE) years and 56.5% were females. We classified 2,246 (50.4%), 2,195 (40.3%), and 541 (9.2%) individuals as robust, pre-frail and frail, respectively. Percent BF was 35.9±0.13, 38.3±0.20 and 40.0±0.46 in the robust, pre-frail and frail individuals, respectively. WC was 99.5±0.32 in the robust, 100.1±0.43 in pre-frail, 104.7±1.17 in frail individuals. Compared to robust individuals, only frail individuals had greater %BF on average (β=0.97±0.43,p=0.03); however, pre-frail and frail individuals had 2.18 and 4.80 greater WC, respectively (β=2.18±0.64,p=0.002, and β=4.80±1.1,p<0.001).

CONCLUSION

Our results demonstrate that in older adults, frailty and pre-frailty are associated with a greater likelihood of high WC (as dichotomized) and a greater average WC (continuous).

Fit4YAMs: Structuring a Lifestyle Intervention for Rural Overweight and Obese Young Adult Males Using Participatory Design

PURPOSE

Young adult males (YAMs) are understudied with respect to lifestyle interventions to address overweight and obesity in this group. This study reports on the participatory design of the structure and delivery of the Fit4YAMs text message-based lifestyle intervention for 18- to 25-year-old rural YAMs in Australia.

METHODS

Two semi-structured focus group discussions were held with six overweight or obese YAMs. Sessions explored their preferences for the structure and delivery of a weight loss intervention. Focus groups were recorded, and the contents transcribed verbatim for thematic analysis.

RESULTS

The YAMs were unanimous in their preference for a highly personalized intervention program, complete with personalized goal setting, personalized motivation and engagement strategies, and personalized text message content. A text message frequency of three-four messages per week was deemed optimal for this group. Minimal direct contact by the intervention team was requested, but with clear guidelines and reminders of key contacts whom they could contact should they require help and guidance. The YAMs also agreed that a comprehensive goal setting session and personalization session prior to commencement of the intervention would be best.

CONCLUSIONS

To engage rural YAMs in lifestyle interventions, a high degree of personalization of the program appears important. Although initially more time and resource intensive than a less personalized approach, it is essential to identify strategies to prevent and reverse weight gain in this hard to engage group. Maximizing their engagement using a more personalized approach could be the key to promoting long-term health outcomes in this group.

Comparative effectiveness of two stabilization exercise positions on pain and functional disability of patients with low back pain

The study investigated the effects of two stabilization exercise positions (prone and supine) on pain intensity (PI) and functional disability (FD) of patients with nonspecific chronic low back pain (NSCLBP). The 56 subjects that completed the study were randomly assigned into stabilization in prone (SIP) (n=19), stabilization in supine (SIS) (n=20), and prone and supine (SIPS) position (n=17) groups. Subjects in all the groups received infrared radiation for 15 min and kneading massage at the low back region. Subjects in SIP, SIS, and SIPS groups received stabilization exercise in prone lying, supine lying and combination of both positions respectively. Treatment was applied twice weekly for eight weeks. PI and FD level of each subject were measured at baseline, 4th and 8th week of the treatment sessions. Data were analyzed using descriptive and inferential statistics. The alpha level was set at P<0.05. Within-group comparison indicated that PI and FD at the 4th and 8th week were significantly reduced (P<0.001) when compared with baseline in all the three groups. However, the result showed that there was no significant difference in the PI and FD at the 8th week (P>0.05) of the treatment sessions across the three groups when compared. It can be concluded that stabilization exercises carried out in prone, supine and combination of the two positions were equally effective in managing pain and disability of patients with NSCLBP. However, no position was superior to the other.

Freshman 15 in England: a longitudinal evaluation of first year university student's weight change

Background

Weight change in first year university students, often referred to as ‘Freshman 15’, has been shown to be a common problem in North America. Studies have reported weight gain to be between 1 kg and 4 kg over the academic year and a recent meta-analysis found a mean gain of 1.34 kg and that 61 % of students gained weight. A limited number of studies have investigated weight change in England and large scale studies are needed to understand better weight change trends and to conduct subgroup analyses. This is important in the context of rising obesity prevalence, especially as behaviours and unhealthy weight in early adulthood often remains over the lifetime.

Methods

We recruited students across 23 universities in England to complete a web-based survey at three time points in 2014–2015: beginning of academic year, December, end of academic year. Students were asked to self-report height and weight. We calculated weight change of each student between time points and conducted t-tests and pared analysis of variance to investigate the effect of time, sex and initial BMI. We also investigated weight change amongst weight gainers and in weight losers separately.

Results

We followed 215 students over three time points and found a mean weight change of 0.98 kg (95%CI 0.49–1.47) over a mean length of 34 weeks of follow-up. The weight change rate was not significantly different over different terms. Over 51 % of the sample gained more than 0.5 kg by the end of the academic year, with a mean gain of 3.46 kg. Female weight gainers had a significantly lower baseline weight than non-weight gaining females. Twenty-five percent of the sample lost more than 0.5 kg with a mean of −3.21 kg. Within weight losers, males lost significantly more weight than females.

Conclusion

Our findings reinforce that the first year of university is a crucial time in the life of students during which the majority tend to gain weight. However, we also found that 25 % lost weight, indicating that 75 % of students undergo a meaningful weight change in their first year. Universities must recognise their role in promoting healthy weight maintenance.

Changes in adiposity in an older Chinese population in rapid economic transition

OBJECTIVE

To examine the changes in body mass index (BMI) and waist circumference (WC) in Guangzhou, South China, which is probably experiencing the most rapid economic transition in history.

METHODS

In this study, 17,786 Chinese aged 50+ years were recruited from 2003 to 2008 and followed up until 2012. BMI and WC were measured at two time points.

RESULTS

During the mean follow-up of 3.6 years (median = 3, interquartile = 1), age-adjusted mean BMI increased only slightly. By contrast, mean WC increased sharply by 0.94 cm (95% confidence interval 0.93-0.94) annually in men and 1.29 cm (1.28-1.29) annually in women. In 77% of women and 69% of men, WC increased, and among them, the mean annual increase was 2.01 cm and 1.70 cm, respectively. Among healthy, never-smoking participants, the incidence of central obesity was 29.0% (36.4% in women and 14.2% in men). The incidence of general obesity was 1.9% and was similarly low in both men and women (2.1% vs. 1.8%). Conversely, 20.3% of individuals with general obesity became nonobese, and 12.8% of individuals with central obesity returned to normal.

CONCLUSIONS

Central obesity has risen sharply in this cohort. Such increases may have been greatly underestimated previously and should form the basis of an even stronger warning for regions undergoing economic transitions in China and elsewhere.

Changes in waist circumference and the prevalence of abdominal obesity during 1994-2008 - cross-sectional and longitudinal results from two surveys: the Tromsø Study

BACKGROUND

Abdominal obesity increases all-cause mortality and is a risk factor for a number of diseases. There are few population-based studies of the longitudinal changes of abdominal obesity.

METHODS

Based on data from the Tromsø Study, we studied gender- and age-specific mean waist circumference and prevalence of abdominal overweight and abdominal obesity in two surveys in 1994-1995 (Tromsø 4, 6812 men and women aged 25 to 84) and 2007-2008 (Tromsø 6, 12,493 men and women aged 30 to 87). Furthermore, we describe the longitudinal changes of waist circumference and abdominal obesity during 13 years in 3144 subjects (aged 25-69 in 1994) who attended both surveys.

RESULTS

Cross-sectional analyses found a higher mean waist circumference in men than women and a direct relationship with age in both men and women in both Tromsø 4 and in Tromsø 6. As the WHO cut-off points for abdominal obesity are gender-specific, however, the prevalence of abdominal obesity was lower in men than in women. In 2007-2008, approximately 37 and 55 % of men and women, respectively, were classified as abdominally obese. Thirteen years before, in 1994-1995, the corresponding figures were 20 and 35 %. Longitudinal analyses of changes during the 13-year period clearly demonstrated that mean waist circumference increased in all examined birth cohorts in both men (mean change 6.1 cm) and women (mean change 8.4 cm), but increased more markedly the younger the subjects were. The prevalence of abdominal obesity in men aged 25-34 increased from 5 % in 1994 to 31 % 13 years later. The prevalence of abdominal obesity more than doubled among both men and women.

CONCLUSIONS

The increasing mean waist circumference is of concern. There is a need for further longitudinal studies of the changes in waist circumference.

Changing guards: time to move beyond body mass index for population monitoring of excess adiposity

With the obesity epidemic, and the effects of aging populations, human phenotypes have changed over two generations, possibly more dramatically than in other species previously. As obesity is an important and growing hazard for population health, we recommend a systematic evaluation of the optimal measure(s) for population-level excess body fat. Ideal measure(s) for monitoring body composition and obesity should be simple, as accurate and sensitive as possible, and provide good categorization of related health risks. Combinations of anthropometric markers or predictive equations may facilitate better use of anthropometric data than single measures to estimate body composition for populations. Here, we provide new evidence that increasing proportions of aging populations are at high health-risk according to waist circumference, but not body mass index (BMI), so continued use of BMI as the principal population-level measure substantially underestimates the health-burden from excess adiposity.

Quantifying the proportion of deaths due to body mass index- and waist circumference-defined obesity

OBJECTIVE

To determine the risk of mortality associated with and quantify the deaths attributable to combinations of body mass index (BMI) and waist circumference (WC).

METHODS

This study included 41,439 participants. For the hazard ratio (HR) calculation, adiposity categories were defined as: BMI(N) /WC(N) , BMI(N) /WC(O) , BMI(O) /WC(N) , and BMI(O) /WC(O) (N = non-obese, O = obese). For the population attributable fraction analysis, obesity was classified as: (i) obese by BMI and/or WC; (ii) obese by BMI; and (iii) obese by WC. Mortality data was complete to the end of 2012.

RESULTS

The prevalence of BMI(N) /WC(N) , BMI(N) /WC(O) , BMI(O) /WC(N) , and BMI(O) /WC(O) was 73%, 6%, 6%, and 15%, respectively. There was an increased risk of all-cause and cardiovascular disease (CVD) mortality in those with BMI(N) /WC(O) (HR (95% CI) 1.2 (1.2, 1.3) and 1.3 (1.1, 1.6)) and BMI(O) /WC(O) (1.3 (1.3, 1.4) and 1.7 (1.5, 1.9)) compared to those with BMI(N) /WC(N) . The estimated proportion of all-cause and CVD mortality attributable to obesity defined using WC or using BMI and/or WC was higher compared to obesity defined using BMI.

CONCLUSIONS

Current population obesity monitoring misses those with BMI(N) /WC(O) who are at increased risk of mortality. By targeting reductions in population WC, the potential exists to prevent more deaths in the population than if we continue to target reductions in BMI alone.

Estimating the proportion of metabolic health outcomes attributable to obesity: a cross-sectional exploration of body mass index and waist circumference combinations

BACKGROUND

Recent evidence suggests that a substantial subgroup of the population who have a high-risk waist circumference (WC) do not have an obese body mass index (BMI). This study aimed to explore whether including those with a non-obese BMI but high risk WC as 'obese' improves prediction of adiposity-related metabolic outcomes.

METHODS

Eleven thousand, two hundred forty-seven participants were recruited. Height, weight and WC were measured. Ten thousand, six hundred fifty-nine participants with complete data were included. Adiposity categories were defined as: BMI(N)/WC(N), BMI(N)/WC(O), BMI(O)/WC(N), and BMI(O)/WC(O) (N = non-obese and O = obese). Population attributable fraction, area under the receiver operating characteristic curve (AUC), and odds ratios (OR) were calculated.

RESULTS

Participants were on average 48 years old and 50 % were men. The proportions of BMI(N)/WC(N), BMI(N)/WC(O), BMI(O)/WC(N) and BMI(O)/WC(O) were 68, 12, 2 and 18 %, respectively. A lower proportion of diabetes was attributable to obesity defined using BMI alone compared to BMI and WC combined (32 % vs 47 %). AUC for diabetes was also lower when obesity was defined using BMI alone (0.62 vs 0.66). Similar results were observed for all outcomes. The odds for hypertension, dyslipidaemia, diabetes and CVD were increased for those with BMI(N)/WC(O) (OR range 1.8-2.7) and BMI(O)/WC(O) (OR 1.9-4.9) compared to those with BMI(N)/WC(N).

CONCLUSIONS

Current population monitoring, assessing obesity by BMI only, misses a proportion of the population who are at increased health risk through excess adiposity. Improved identification of those at increased health risk needs to be considered for better prioritisation of policy and resources.

Elearning approaches to prevent weight gain in young adults: A randomized controlled study

OBJECTIVE

Preventing obesity among young adults should be a preferred public health approach given the limited efficacy of treatment interventions. This study examined whether weight gain can be prevented by online approaches using two different behavioral models, one overtly directed at obesity and the other covertly.

METHODS

A three-group parallel randomized controlled intervention was conducted in 2012-2013; 20,975 young adults were allocated a priori to one control and two "treatment" groups. Two treatment groups were offered online courses over 19 weeks on (1) personal weight control ("Not the Ice Cream Van," NTICV) and, (2) political, environmental, and social issues around food ("Goddess Demetra," "GD"). Control group received no contact. The primary outcome was weight change over 40 weeks.

RESULTS

Within-group 40-week weight changes were different between groups (P < 0.001): Control (n = 2,134): +2.0 kg (95% CI = 1.5, 2.3 kg); NTICV (n = 1,810): -1.0 kg (95% CI = -1.3, -0.5); and GD (n = 2,057): -1.35 kg (95% CI = -1.4 to -0.7). Relative risks for weight gain vs.

CONTROL

NTICV = 0.13 kg (95% CI = 0.10, 0.15), P < 0.0001; GD = 0.07 kg (95% CI = 0.05, 0.10), P < 0.0001.

CONCLUSIONS

Both interventions were associated with prevention of the weight gain observed among control subjects. This low-cost intervention could be widely transferable as one tool against the obesity epidemic. Outside the randomized controlled trial setting, it could be enhanced using supporting advertising and social media.

Effects of calorie labelling on macro- and micro-nutrients in main-meal choices made by young adults

BACKGROUND/OBJECTIVES

There is limited evidence that prominent calorie labelling on out-of-home meals helps consumers reduce calorie intakes and avoid weight gain, but no evidence on its effects on macro- and micro-nutrients. The objective of this study was to assess the impact of prominent calorie labelling on energy, macro- and micro-nutrients.

SUBJECTS/METHODS

Young adults in a catered residential setting were observed when choosing main meals over three study periods in fixed order in this observational study. Period 1: with calorie labels (20 weeks); period 2: without calorie labels (10 weeks); period 3: with calorie labels plus information on estimated energy requirements (10 weeks). Nutrient contents of meal choices were analysed from food composition tables.

RESULTS

Energy, 4 macronutrients and 19 micronutrients levels were derived from 4200 meals chosen by 120 subjects over 40 weeks. Means (s.d. or Median) for key macro- and micro-nutrients were for period 1: energy=658 (94) kcal, fat=31 (8.6) g, saturated fat=10.5 (2.7) g, B12=2.5 (1.7) μg, folate=119 (46.8) μg, vitamin C=80.0 (42) mg, Ca=278 (129) mg, Na=1230 (119) mg, Fe=22 (10) g, Se=19 (10.1) μg, I=34 (10.1) μg, period 2: energy=723 (87) kcal, fat=35 (7.6) g, saturated fat=12 (2.7) g, B12=3.4 (1.7) μg, Folate=182 (13.3) μg, vitamin C=87.0 (49.7) mg, Ca=379 (149) mg, Na=1352 (114) mg, Fe=41.6 (14) g, Se=26 (10.3) μg, I=38.0 (18.4) μg, period 3: energy=578 (109) kcal, fat=27.3 (9.1) g, saturated fat=8.5 (2.7) g, B12=2.2 (0.5) μg, Folate=90 (50.8) μg, vitamin C=75.0 (34) mg, Ca=277 (119) mg, Na=1205 (99) mg, Fe=14.5 (10.9) g, Se=15.0 (10) μg, I=32.0 (18.4) μg. All macro- and micro-nutrients, except for B1, vitamin C, vitamin E and Ca were significantly different between the three periods (P<0.001), but all mean intakes remained above recommended levels.

CONCLUSIONS

Calorie labelling resulted in reductions in calories, fat and saturated fat contents of the meals chosen, without compromising micronutrient consumptions.

Soft drink consumption is positively associated with increased waist circumference and 10-year incidence of abdominal obesity in Spanish adults

BACKGROUND

The accumulation of abdominal fat increases risk of metabolic disorders and premature death. There is a dearth of prospective data on the association between caloric beverage consumption and surrogate markers of abdominal adiposity.

OBJECTIVE

The aim of this study was to assess the relation between consumption of nonalcoholic caloric beverages, including soft drinks, fruit juice, whole milk, and skim and low-fat milk, and changes in waist circumference (WC) and odds of 10-y incidence of abdominal obesity.

METHODS

We conducted a prospective, population-based study of 2181 Spanish men and women aged 25-74 y who were followed from 2000 to 2009. We measured weight, height, and WC, and recorded data on diet and leisure-time physical activity (LTPA) with the use of validated questionnaires. We fit multivariable linear and logistic regression models.

RESULTS

A 100 kcal increase in soft drink consumption was associated with a 1.1 cm increase in WC (P = 0.018) after 10 y of follow-up. Substitution of 100 kcal of soft drinks with 100 kcal of whole milk or 100 kcal of juice was associated with a 1.3 cm (95% CI: 0.3, 2.4) and 1.1 cm (95% CI: 0.03, 2.2) decrease in WC, respectively. Increasing consumption of soft drinks from baseline to follow-up led to WC gain compared with maintaining nonconsumption. Greater soft drink consumption was positively associated (P = 0.029) with increased odds of 10-y incidence of abdominal obesity.

CONCLUSION

Adults' consumption of soft drinks was associated with increased WC and odds of 10-y incidence of abdominal obesity. This association was moderate but consistent in all statistical models.

Preventing weight gain with calorie-labeling

OBJECTIVE

Calorie-labeling has been suggested as an anti-obesity measure but there is no evidence for its effect, to date. Early adulthood is a critical life-cycle period for unwanted weight gain and obesity development. This study examined whether providing calorie information would help young adults to avoid weight gain.

METHODS

Using a pragmatic interrupted time-series study design, weight changes over 36 weeks were reported among two year-groups, each of 120 young adults, similar in age, gender, and ethnicity, living in fully-catered accommodation. Year 1: subjects were observed without calorie-labeling, apart from a 5-week pilot. Year 2: calorie-labeling was present prominently and consistently at main meals for 30 of the 36 weeks.

RESULTS

Mean weight changes over 36 weeks, per protocol, were +3.5 kg (95% CI = 2.8-4.1 kg) (n = 64) in Year 1 and -0.15 kg (95% CI = -0.7-0.3 kg) (n = 87) in Year 2. Weight changes were significantly different between years, for males and females (both P < 0.001). Intention-to-treat analysis showed similar results. Relative Risk for weight gain in Year 2, compared to Year 1, was 0.5 (P < 0·0001).

CONCLUSIONS

Calorie-labeling was associated with a 3.5 kg less weight gain, representing a low-cost "nudging" approach to combat the rapid weight gain seen in young adults.

Trends in the skewness of the body mass index distribution among urban Australian adults, 1980 to 2007

PURPOSE

We analyzed the changes in the body mass index (BMI) distribution for urban Australian adults between 1980 and 2007.

METHODS

We used data from participants of six consecutive Australian nation-wide surveys with measured weight and height between 1980 and 2007. We used quantile regression to estimate mean BMI (for percentiles of BMI) and prevalence of severe obesity, modeled by natural splines in age, date of birth, and survey date.

RESULTS

Since 1980, the right skew in the BMI distribution for Australian adults has increased greatly for men and women, driven by increases in skew associated with age and birth cohort/period. Between 1980 and 2007, the average 5-year increase in BMI was 1 kg/m(2) (0.8) for the 95th percentile of BMI in women (men). The increase in the median was about a third of this, and for the 10th percentile, a fifth of this. We estimated that for the cohort born in 1960 around 31% of men and women were obese by age 50 years compared with 11% of the 1930 birth cohort.

CONCLUSIONS

There have been large increases in the right skew of the BMI distribution for urban Australian adults between 1980 and 2007, and birth cohort effects suggests similar increases are likely to continue.

Weight changes in young adults: a mixed-methods study

OBJECTIVE

In both the United States and United Kingdom, countries with high prevalence of obesity, weight gain is particularly rapid in young adulthood and especially identified among first-year students.

DESIGN

A triangulation protocol was used, incorporating quantitative and qualitative research methods. A 27-question online survey was sent to all first-year undergraduates twice, with a 9-month interval. An online focus group was conducted at the end of the year, analysed by content and thematically. Self-reported weights and heights were validated against objectively measured data.

RESULTS

From a total of 3010 first-year students, 1440 (female=734) responded at baseline mean (s.d.) age 20 (3.6) years, body mass index 22.3 (4.6) kg m(-2), 17% smokers and 80% alcohol drinkers. At follow-up, 1275 students reported a mean weight change of 1.8 (s.d. 2.6) kg over the 9-month period. Self-reported data correlated strongly with measured weights (r=0.999, P<0.001) and heights (r=0.998, P<0.001). Predictors of weight gain were baseline weight (P<0.001). Dairy products consumption was associated with less weight gain (P<0.001). Fruit and vegetable consumption, and time spent on physical activity or sleeping were associated with neither weight gain nor weight loss. Focus group content analysis revealed weight gain as a major concern, reported by half the participants, and increased alcohol consumption was considered the most common lifestyle change behind weight gain. Thematic analysis identified three main themes as barriers to or facilitators of healthy lifestyles and weight; budget, peer influence and time management.

CONCLUSIONS

Rapid weight gain is of concern to young adults. Students living away from home are at particular risk, owing to specific obesogenic behaviours. Consumption of fruit and vegetables, and physical activity, despite popular beliefs, were not associated with protection against weight gain.

Sarcopenia, sarcopenic obesity and mortality in older adults: results from the National Health and Nutrition Examination Survey III

BACKGROUND

Sarcopenia is defined as the loss of skeletal muscle mass and quality, which accelerates with aging and is associated with functional decline. Rising obesity prevalence has led to a high-risk group with both disorders. We assessed mortality risk associated with sarcopenia and sarcopenic obesity in elders.

METHODS

A subsample of 4652 subjects ≥60 years of age was identified from the National Health and Nutrition Examination Survey III (1988-1994), a cross-sectional survey of non-institutionalized adults. National Death Index data were linked to this data set. Sarcopenia was defined using a bioelectrical impedance formula validated using magnetic resonance imaging-measured skeletal mass by Janssen et al. Cutoffs for total skeletal muscle mass adjusted for height(2) were sex-specific (men: ≤5.75 kg/m(2); females ≤10.75 kg/m(2)). Obesity was based on % body fat (males: ≥27%, females: ≥38%). Modeling assessed mortality adjusting for age, sex, ethnicity (model 1), comorbidities (hypertension, diabetes, congestive heart failure, osteoporosis, cancer, coronary artery disease and arthritis), smoking, physical activity, self-reported health (model 2) and mobility limitations (model 3).

RESULTS

Mean age was 70.6±0.2 years and 57.2% were female. Median follow-up was 14.3 years (interquartile range: 12.5-16.1). Overall prevalence of sarcopenia was 35.4% in women and 75.5% in men, which increased with age. Prevalence of obesity was 60.8% in women and 54.4% in men. Sarcopenic obesity prevalence was 18.1% in women and 42.9% in men. There were 2782 (61.7%) deaths, of which 39.0% were cardiovascular. Women with sarcopenia and sarcopenic obesity had a higher mortality risk than those without sarcopenia or obesity after adjustment (model 2, hazard ratio (HR): 1.35 (1.05-1.74) and 1.29 (1.03-1.60)). After adjusting for mobility limitations (model 3), sarcopenia alone (HR: 1.32 ((1.04-1.69) but not sarcopenia with obesity (HR: 1.25 (0.99-1.58)) was associated with mortality. For men, the risk of death with sarcopenia and sarcopenic obesity was nonsignificant in both model-2 (HR: 0.98 (0.77-1.25), and HR: 0.99 (0.79-1.23)) and model 3 (HR: 0.98 (0.77-1.24) and HR: 0.98 (0.79-1.22)).

CONCLUSIONS

Older women with sarcopenia have an increased all-cause mortality risk independent of obesity.

Twelve-year weight change, waist circumference change and incident obesity: the Australian diabetes, obesity and lifestyle study

OBJECTIVE

This study aimed to describe the changes in weight and waist circumference (WC), examine the incidence of obesity as defined by body mass index (BMI) and WC, and describe the changes in the prevalence of obesity over 12 years.

METHODS

In 1999/2000, 11,247 adults aged ≥25 years were recruited from 42 randomly selected areas across Australia. In total, 44.6% of eligible participants completed follow-up in 2011/12. Height, weight, and WC were measured at both surveys.

RESULTS

People who were 25-34 years of age at baseline gained an average of 6.7 kg weight and 6.6 cm WC, whereas those aged ≥75 years lost an average of 4.5 kg and gained an average of 0.8 cm. Women had a greater increase in WC than men, but did not differ in terms of weight gain. The 12-year incidence of obesity was 15.0% when defined by BMI and 31.8% when defined by WC. According to BMI and WC combined, the percentage of the cohort that was normal weight decreased from 33 to 21% and the percentage that was obese increased from 32 to 49% between baseline and 2012.

CONCLUSIONS

In addition to BMI, assessment of WC should be incorporated more frequently when assessing population trends of obesity and the burden of disease associated with excess adiposity.

Predicting muscle mass from anthropometry using magnetic resonance imaging as reference: a systematic review

Identification and management of sarcopenia are limited by lack of reliable simple approaches to assess muscle mass. The aim of this review is to identify and evaluate simple methods to quantify muscle mass/volume of adults. Using Cochrane Review methodology, Medline (1946-2012), Embase (1974-2012), Web of Science (1898-2012), PubMed, and the Cochrane Library (to 08/2012) were searched for publications that included prediction equations (from anthropometric measurements) to estimate muscle mass by magnetic resonance imaging (MRI) in adults. Of 257 papers identified from primary search terms, 12 studies met the inclusion criteria. Most studies (n = 10) assessed only regional/limb muscle mass/volume. Many studies (n = 9) assessed limb circumference adjusted for skinfold thickness, which limits their practical applications. Only two included validation in separate subject-samples, and two reported relationships between whole-body MRI-measured muscle mass and anthropometry beyond linear correlations. In conclusion, one simple prediction equation shows promise, but it has not been validated in a separate population with different investigators. Furthermore, it did not incorporate widely available trunk/limb girths, which have offered valuable prediction of body composition in other studies.