Longitudinal changes in body composition in older men and women: role of body weight change and physical activity

BACKGROUND: Estimates of body-composition change in older adults are mostly derived from cross-sectional data. OBJECTIVE: We examined the natural longitudinal patterns of change in fat-free mass (FFM) and fat mass (FM) in older adults and explored the effect of physical activity, weight change, and age on these changes. DESIGN: The body composition measured by hydrodensitometry and the level of sports and recreational activity (SRA) of 53 men and 78 women with a mean (+/-SD) initial age of 60.7 +/- 7.8 y were examined on 2 occasions separated by a mean (+/-SD) time of 9.4 +/- 1.4 y. RESULTS: FFM decreased in men (2.0% per decade) but not in women, whereas FM increased similarly in both sexes (7.5% per decade). Levels of SRA decreased more in men than in women over the follow-up period. Baseline age and level of SRA were inversely and independently associated with changes in FM in women only. Neither age nor level of SRA was associated with changes in FFM in men or women. Weight-stable subjects lost FFM. FFM accounted for 19% of body weight in those who gained weight, even in the presence of decreased levels of SRA. Loss of FFM (33% of body weight) was pronounced in those who lost weight, despite median SRA levels >4184 kJ/wk. CONCLUSIONS: On average, FM increased; however, the increase in women was attenuated with advancing age. The decrease in FFM over the follow-up period was small and masked the wide interindividual variation that was dependent on the magnitude of weight change. The contribution of weight stability, modest weight gains, or lifestyle changes that include regular resistance exercise in attenuating lean-tissue loss with age should be explored.     

Eight-year longitudinal changes in body composition in healthy Swiss adults

OBJECTIVE: Significant changes in body composition occur during lifetime. This longitudinal study (8.0 +/- 0.8 yrs) in a cohort of healthy sedentary and physically active men (n = 78) and women (n = 53), aged 20 to 74 yr describes: 1) the longitudinal changes in weight and body composition and 2) their associations with age and physical activity. Method: Fat-free mass (FFM) and body fat (BF) were assessed by bioelectrical impedance analysis (BIA). Subjects who regularly performed >3 hours per week of endurance type physical activity were classified as "Active". Others were classified as "Sedentary". Subjects were also separated by age (<45 yr vs > or =45 yr). RESULTS: FFM increased by 1.7 +/- 2.8 kg in men <45 yr who gained 4.0 +/- 5.0 kg of body weight and was maintained (0.5 +/- 1.6 kg) in women <45 y who gained 1.6 +/- 3.0 kg of weight. A weight gain of 1.2 +/- 3.3 kg in men > or =45 yr was accompanied by stable FFM (-0.1 +/- 2.3 kg), and of 1.0 +/- 3.2 kg was accompanied by a loss of FFM in women > or =45 yr. In active men > or =45 yr, maintenance of FFM was associated with smaller weight gains than in sedentary; sedentary men > or =45 yr decreased FFM with larger weight gains than active subjects. Sedentary women <45 yr were able to gain FFM; the active women maintained, but did not gain FFM with smaller weight gains than in sedentary women. FFM decreased in >/=45 yr women despite of small weight gains. CONCLUSION: Weight change is clearly associated with a change in FFM. Weight gain is necessary to offset age-related FFM loss between 20 and 74 yrs. In active men, a FFM increase was associated with less weight gain than sedentary men. Future studies should evaluate the threshold of weight change and the level of physical activity necessary to prevent age-related losses of FFM.     

Eight-Year Longitudinal Changes in Body Composition in Healthy Swiss Adults

Objective: Significant changes in body composition occur during lifetime. This longitudinal study (8.0 ± 0.8 yrs) in a cohort of healthy sedentary and physically active men (n = 78) and women (n = 53), aged 20 to 74 yr describes: 1) the longitudinal changes in weight and body composition and 2) their associations with age and physical activity.

Method: Fat-free mass (FFM) and body fat (BF) were assessed by bioelectrical impedance analysis (BIA). Subjects who regularly performed >3 hours per week of endurance type physical activity were classified as “Active”. Others were classified as “Sedentary”. Subjects were also separated by age (<45 yr vs ≥45 yr).

Results: FFM increased by 1.7 ± 2.8 kg in men <45 yr who gained 4.0 ± 5.0 kg of body weight and was maintained (0.5 ± 1.6 kg) in women <45 y who gained 1.6 ± 3.0 kg of weight. A weight gain of 1.2 ± 3.3 kg in men ≥45 yr was accompanied by stable FFM (?0.1 ± 2.3 kg), and of 1.0 ± 3.2 kg was accompanied by a loss of FFM in women ≥45 yr. In active men ≥45 yr, maintenance of FFM was associated with smaller weight gains than in sedentary; sedentary men ≥45 yr decreased FFM with larger weight gains than active subjects. Sedentary women <45 yr were able to gain FFM; the active women maintained, but did not gain FFM with smaller weight gains than in sedentary women. FFM decreased in ≥45 yr women despite of small weight gains.

Conclusion: Weight change is clearly associated with a change in FFM. Weight gain is necessary to offset age-related FFM loss between 20 and 74 yrs. In active men, a FFM increase was associated with less weight gain than sedentary men. Future studies should evaluate the threshold of weight change and the level of physical activity necessary to prevent age-related losses of FFM.     

Physical activity energy expenditure predicts changes in body composition in middle-aged healthy whites: effect modification by age

BACKGROUND: It is unclear whether physical activity energy expenditure (PAEE) predicts changes in body composition. OBJECTIVE: The objective was to describe the independent associations between PAEE and changes in body composition in a population-based cohort. DESIGN: This was a prospective population-based study conducted in 739 (311 men and 428 women) healthy middle-aged (median age: 53.8 y) whites. The median follow-up was 5.6 y. PAEE (MJ/d) was assessed by heart rate monitoring, individually calibrated by using the FLEX heart rate method. Fat mass (FM) and fat-free mass (FFM) were assessed by bioimpedance. RESULTS: Body weight (BW) at follow-up was significantly related to baseline PAEE (P < 0.05) after adjustment for sex, baseline age, FM, FFM, and follow-up time. A significant interaction between PAEE and age (P = 0.023) was observed. After the subjects were stratified (above and below the median for age), BW increased by a mean (+/-SD) of 1.7 +/- 5.9 kg (P < 0.0001) in the younger cohort. In this group, follow-up FM was significantly associated with baseline PAEE (P = 0.036) after adjustment for confounders. In the older cohort, BW did not change between baseline and follow-up. In this group, in contrast with the younger population, follow-up BW, FM, and FFM were all significantly and positively associated with baseline PAEE (P < 0.01 for all). CONCLUSIONS: Baseline PAEE predicts a change in FM in younger adults, who as a group gained weight in this study. In contrast, baseline PAEE in older adults--who were on average weight stable--is associated with a gain in BW, which was explained by an increase in FM and FFM.     

Age-related differences in fat-free mass, skeletal muscle, body cell mass and fat mass between 18 and 94 years

OBJECTIVE: To determine (1) lean and fat body compartments, reflected by fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), body cell mass (BCM), total body potassium (TBK), fat mass and percentage fat mass, and their differences between age groups in healthy, physically active subjects from 18 to 94 y of age; and (2) if the rate of decrease in any one of the parameters by age might be accelerated compared to others. METHODS: A total of 433 healthy ambulatory Caucasians (253 men and 180 women) aged 18--94 y were measured by dual-energy X-ray absorptiometry (DXA) and whole body scintillation counter (TBK counter) using a large sodium iodide crystal (203 mm diameter). RESULTS: The ASMM change (-16.4 and -12.3% in men and women, respectively) in >75 y-old compared to 18 to 34-y-old subjects was greater than the FFM change (-11.8 and -9.7% in men and women, respectively) and this suggests that skeletal muscle mass decrease in older subjects was proportionally greater than non-skeletal muscle mass. BCM (-25.1 and -23.2% in men and women, respectively) and TBK differences were greater than the differences in FFM or ASMM suggesting altered composition of FFM in older subjects. Women had lower peak FFM, ASMM, BCM and TBK than men. CONCLUSIONS: The decline in FFM, ASMM, BCM and TBK is accelerated in men and women after 60 y of age and FFM, ASMM, BCM and TBK are significantly lower than in younger subjects. Fat mass continued to increase until around 75 y.     

Latent class growth analysis successfully identified subgroups of participants during a weight loss intervention trial

IntroductionWeight loss interventions often present small mean weight changes over time, despite the fact that a substantial proportion of the participants lost more weight. This effect is often leveled out by the substantial proportion of participants who gained weight during the trial. The aim of this study is to identify and describe distinct subgroups of participants with different weight change trajectories during and after a weight loss intervention.MethodsWe used data from a weight loss intervention that was part of a randomized controlled trial on the preventive effect of a tailor-made weight loss intervention and oral glucosamine sulfate on the incidence of knee osteoarthritis in 407 overweight women aged 50 to 60 years. Latent class growth analysis (LCGA) was used to identify subgroups of participants with different weight change trajectories over time.ResultsUsing LCGA, we identified three subgroups with different trajectories of weight change, one large group (n = 298) with almost no change over time, and two smaller groups (both n = 48), of which one represents participants who steadily gained weight over time, whereas the other represents participants who steadily lost weight over time. Participants that had relatively low body weight around their 40th year of life and that gained weight in the year preceding the study were most likely to belong to the group that lost weight.ConclusionLCGA was a suitable method to identify three distinct groups of participants with different trajectories of weight change. Low body weight at age 40 and weight gain in the year preceding the study were associated with a higher chance of membership of the group that lost weight. It seems weight loss that occurred during this weight loss intervention was mostly recently gained weight.     

Evaluation of anthropometric equations to assess body-composition changes in young women

BACKGROUND: Healthy young women who engage in an exercise program may lose fat that is not reflected in body weight changes because of concurrent gains in fat-free mass (FFM). OBJECTIVE: This study addressed the question of how well anthropometry-based predictive equations can resolve these changes. DESIGN: Several widely used skinfold-thickness- or circumference-based equations were compared by using dual-energy X-ray absorptiometry to study 150 healthy young women before and after 8 wk of Army basic combat training (average energy expenditure: 11.7 MJ/d). RESULTS: Women lost 1.2 +/- 2.6 kg fat (mean +/- SD) and gained 2.0 [corrected] +/- 1.5 kg FFM. Fat loss (r = 0.47), but not FFM gain (r = 0.01), correlated with initial fatness. Thus, for many women who lost fat, body weight did not change or increased. Fat loss was associated with a reduction in abdominal circumference but this alone was not a consistent marker of fat loss. One circumference equation and one skinfold-thickness equation yielded the smallest residual SDs (2.0% and 1.9% body fat, respectively) compared with the other equations in predicting body fat. The sensitivity and specificity of the best equations in predicting changes in percentage body fat were not better than 55% and 66%, respectively. CONCLUSIONS: These data suggest that for women, anthropometry can provide better estimates of fatness than body mass index but it is still relatively insensitive to short-term alterations in body composition. Not surprisingly, the circumference equation that includes the most labile sites of female fat deposition (ie, waist and hips instead of upper arm or thigh) proved to be the most reliable.     

Longitudinal study of body composition changes associated with weight change and physical activity

OBJECTIVE: Weight changes result in fat-free mass (FFM) and body fat (BF) changes. This study determined FFM and BF changes after weight gain or loss and whether these changes differ by gender, physical activity, and age. METHODS: Healthy volunteers, recruited between 1991 and 2003, were followed for 1 y (n = 400) or 3 y (n = 305). Active subjects performed >3 h of physical activity of > or =4.0 metabolic equivalents/wk, sedentary subjects performed <3 h/wk. Body weight and body composition by bioelectrical impedance analysis were determined at year 0, 1, or 3. RESULTS: At years 1 and 3, FFM and BF decreased with weight loss and increased with weight gain. BF was more sensitive (P < 0.03) to weight change than FFM. Compared to weight-stable individuals at year 1, weight gains of 1.0-1.9, 2.0-2.9, and > or =3.0 kg changed FFM by -0.04 (P = 0.90), +0.48 (P = 0.15), and +1.39 kg and BF by +1.35, +1.87, and +3.09 kg, respectively (all P < 0.001). Comparable FFM and BF decreases were observed for weight losses (FFM -0.28 kg, P = 0.38; -0.75 kg, P = 0.04; -1.51 kg, P < 0.001; BF -1.01 kg, P < 0.01; -1.55 kg, P = 0.01; -3.13 kg, P < 0.001). These relations were similar across gender and age strata. At year 1, active individuals were less likely to gain BF with weight gain and more likely to lose BF with weight loss than were sedentary individuals, except for weight losses >3 kg. At year 3, the association between body weight and FFM and BF change was similar between active and sedentary individuals. CONCLUSION: Greater weight changes (>3 kg) are necessary for weight change to have a significant effect on FFM than to have an effect on BF.     

Body movement and physical activity energy expenditure in children and adolescents: how to adjust for differences in body size and age

BACKGROUND: Physical activity data in children and adolescents who differ in body size and age are influenced by whether physical activity is expressed in terms of body movement or energy expenditure. OBJECTIVE: We examined whether physical activity expressed as body movement (ie, accelerometer counts) differs from physical activity energy expenditure (PAEE) as a function of body size and age. DESIGN: This was a cross-sectional study in children [n = 26; (+/-SD) age: 9.6 +/- 0.3 y] and adolescents (n = 25; age: 17.6 +/- 1.5 y) in which body movement and total energy expenditure (TEE) were simultaneously measured with the use of accelerometry and the doubly labeled water method, respectively. PAEE was expressed as 1) unadjusted PAEE [TEE minus resting energy expenditure (REE); in MJ/d], 2) PAEE adjusted for body weight (BW) (PAEE. kg(-1). d(-1)), 3) PAEE adjusted for fat-free mass (FFM) (PAEE. kg FFM(-1). d(-1)), and 4) the physical activity level (PAL = TEE/REE). RESULTS: Body movement was significantly higher (P = 0.03) in children than in adolescents. Similarly, when PAEE was normalized for differences in BW or FFM, it was significantly higher in children than in adolescents (P = 0.03). In contrast, unadjusted PAEE and PAL were significantly higher in adolescents (P < 0.01). CONCLUSIONS: PAEE should be normalized for BW or FFM for comparison of physical activity between children and adolescents who differ in body size and age. Adjusting PAEE for FFM removes the confounding effect of sex, and therefore FFM may be the most appropriate body-composition variable for normalization of PAEE. Unadjusted PAEE and PAL depend on body size.     

An audit of dietary treatment modalities and weight loss outcomes in a specialist obesity clinic

Background: Obesity resistant to conventional treatment is often treated in specialist obesity clinics. Very little is known about treatment outcome or best management in this sector of the obese population and there appears to be a deficit of published audits from specialist obesity clinics. Method: Our clinic population was characterized in terms of BMI, gender, ethnicity and age as well as previous weight loss attempts, referral source and reasons for referral. The treatment modality was noted and outcome measured in terms of weight change; losses of 5% or more from presenting body weight were defined as weight loss. Results: It was found that 33% of the attending clinic population ( n =166) lost weight during their treatment phase, although no data was available on the long-term maintenance of this loss. Forty-three per cent lost 0–4% of their body weight, while 25% gained weight during their treatment phase. In the group that gained weight a greater number of patients (24%) reported depressive symptoms and required psychiatric or psychological intervention and/or antidepressive medication compared to only 4% of those patients who had lost weight. The most frequently used dietary modality was the low-fat diet, however, all of the treatment methods resulted in weight loss in some patients but not in others. Of particular interest were those patients who tried a number of different treatment methods before finding one which resulted in weight loss. Conclusion: This audit confirms that different treatment methods suit different individuals and highlights the importance of tailoring dietary advice to the individual patient.     

Associations between prenatal and postnatal growth and adult body size and composition

BACKGROUND: Adult body size and composition (ABSC) measures are associated with work capacity and productivity, reproductive performance, and chronic disease risk. Growth failure in early childhood may have important long-term consequences through its influence on ABSC. OBJECTIVE: We assessed associations between prenatal and postnatal growth (0-2 y of age) and ABSC. DESIGN: We included 267 singletons from a prospective study carried out between 1969 and 1977 in 4 ladino Guatemalan villages. We used data from that study and from a follow-up study conducted in 1998-1999 (when the subjects were 21-27 y of age) to determine associations of birth weight, length at 15 d of age, ponderal index, and length at 2 y of age with adult height, weight, fat-free mass (FFM), fat mass, percentage of body fat, and waist-to-hip ratio. Multivariate linear regression analyses with mixed models were carried out to account for sibling clustering. Two-stage least-squares analyses were used to separate specific effects of prenatal and postnatal growth. RESULTS: Birth weight, length at 15 d of age, and length at 2 y of age were positively associated with height, weight, and FFM in both sexes (P < 0.05). Prenatal growth and postnatal growth were equally important determinants of height, weight, and FFM. Weak positive associations of postnatal growth with adult fat mass and percentage of body fat were found in both sexes, whereas similar associations for prenatal growth were found in women only. Growth in early childhood was not related to waist-to-hip ratio. CONCLUSIONS: Growth retardation in early childhood was associated with shortness and less FFM in adulthood. Preventing growth failure in utero and preventing growth failure during the first 2 y of life are equally important for ABSC.     

Body fat gain and loss differentially influence validity of dual-energy x-ray absorptiometry and multifrequency bioelectrical impedance analysis during simultaneous fat-free mass accretion

The validity of dual-energy x-ray absorptiometry (DXA) and multifrequency bioelectrical impedance analysis (MFBIA) for detecting changes in fat mass (FM), fat-free mass (FFM), and body fat percentage (BF%) was evaluated, as compared to a rapid 4-component (4C) model, in 31 females completing 8 weeks of resistance training. Analyses were performed in all participants (ALL) and in subgroups that gained FFM but lost FM (R subgroup) or gained both FFM and FM (G subgroup). It was hypothesized that methods would comparably detect changes in ALL, but discrepancies would occur in subgroup analysis. Changes in body composition did not significantly differ between 4C, DXA, and MFBIA. Equivalence testing indicated that similar changes were detected by DXA and MFBIA, compared to 4C, for ΔFFM in all analyses and ΔBF% in ALL and R subgroup. ΔFM was equivalent to 4C only in R subgroup for DXA and G subgroup for MFBIA. For ΔFM and ΔBF%, DXA and MFBIA produced similar magnitude errors in ALL. However, DXA exhibited lower error in R subgroup, whereas MFBIA exhibited lower error in G subgroup. For ΔFFM, DXA and MFBIA exhibited relatively similar errors in ALL and R subgroup, although MFBIA displayed proportional bias and weaker correlations with 4C than DXA. In G subgroup, MFBIA exhibited lower errors and a higher correlation with 4C ΔFFM than DXA. Although both DXA and MFBIA may have utility for estimating body composition changes during FFM accretion, DXA may be superior during simultaneous FM loss, whereas MFBIA may produce lower error during simultaneous FM gain.     

Composition (lean and fat tissue) of weight changes in adult Danes

BACKGROUND: Weight loss may be associated with unfavorable changes in body composition not compensated for by subsequent weight gain. OBJECTIVE: We examined the composition of weight change in relation to obesity, previous weight changes, weight-loss attempts, and physical activity. DESIGN: Part of the Danish MONICA (Monitoring Trends in Cardiovascular Disease) project, this was a longitudinal population study of changes in weight and body composition, with examinations in 1982-1983, 1987-1988, and 1993-1994. A total of 1236 men and 1200 women aged 35, 45, 55, or 65 y in 1987-1988 participated. Changes in fat and fat-free mass were measured by bioelectrical impedance. RESULTS: Before adjustment for age-related changes, fat-free mass made up 41% of weight lost and 24% of weight gained in men. In women, loss of fat-free mass (35%) was more than double that of gains (15%). After adjustment, the fractions of weight gained as fat-free mass were not significantly different from the fractions lost. These fractions were independent of age, obesity, and weight changes in the previous 5 y; successful weight-loss attempts; and physical activity. Independent of age and degree of obesity, weight changes were associated with greater changes in fat-free mass in men than in women. CONCLUSIONS: These data do not support the theory that weight loss or weight cycling may lead to an unfavorable body composition, nor do they provide a biological explanation for why long-term weight loss is often unsuccessful. However, the metabolic and health consequences of weight change may differ in men and women.     

Patterns of long-term change in body composition are associated with diet, activity, income and urban residence among older adults in China

Studies describing patterns of long-term change in body composition are lacking. Using longitudinal data on 608 healthy, nonobese Chinese (aged 50-70 y) from the 1993 and 1997 China Health and Nutrition Surveys, this article describes the prevalence, sociodemographic and lifestyle correlates of patterns of long-term change in midarm muscle area (MAMA) and body fat (waist circumference). All patterns of change (loss, maintenance [Delta < 1.3 cm(2)], or gain of MAMA with concurrent loss, maintenance [Delta < 2 cm(2)] or gain of body fat), were observed for this sample. After controlling for sex, baseline age, urban residence, height, weight, income, MAMA, waist circumference, smoking status, activity level, mean daily energy and protein intakes (from three 24-h recalls), and change in height, it was determined that subjects who lost both arm muscle and body fat were distinguished from subjects who lost arm muscle but gained body fat by lower income and energy intake at baseline. Although protein intakes at baseline did not differ between the groups that lost arm muscle, protein intakes were significantly higher for subjects who gained both muscle and fat. Patterns of change involving gains in arm muscle were associated with increased protein intake, urban residence, as well as moderate or heavy levels of physical activity at baseline. Variation in protein intake, physical activity, and urban residence also differentiated between the groups that gained fat. Patterns of age-related change in body composition appear associated with modifiable variables, including income, urban residence, activity and protein and energy intake.     

Short-term weight changes in community-dwelling older adults: the Health, Aging, and Body Composition Weight Change Substudy

BACKGROUND: The frequency and short-term natural history of weight loss in community-dwelling older adults have not been described. Unintentional weight loss may be more likely to continue than intentional weight loss. OBJECTIVES: The present substudy described the frequency of a > or = 5% loss or gain in body weight in community-dwelling older adults at an annual examination of the Health, Aging, and Body Composition (Health ABC) Study and 6 mo later. The weight-management practices used by the participants were also described. DESIGN: A total of 522 older adults with either a > or = 5% weight gain (n = 116) or a > or = 5% weight loss (n = 171) in the previous year were compared with a random sample of weight-stable older adults (< 5% weight loss or gain, n = 235) at the fourth annual visit of the ongoing Health ABC Study. The participants' weight-loss intention and weight-management practices were assessed by an interview. The participants' weight was reassessed 6 mo later. RESULTS: Compared with the weight-stable participants, the participants who had lost or gained weight at the substudy baseline were more likely to have subsequent weight changes. The direction of the subsequent weight change, however, was more likely toward either maintenance of or recovery from the previous weight change. Only 4% of the participants who gained weight and 11% of those who lost weight continued to gain or lose weight, respectively. Continued weight loss was more common in the participants with unintentional weight loss than in those with intentional weight loss, but the difference was not significant. CONCLUSIONS: Weight changes were common, but most participants, including those who unintentionally lost weight, maintained their weight change or resolved their weight change in 6 mo. Unintentional weight loss appears less likely to resolve than other weight changes.     

Body composition in HIV-infected children: relations with disease progression and survival.

BACKGROUND: Malnutrition is common in HIV-infected children, but the body compartment that is most affected has been ill defined. OBJECTIVES: Our objectives were to 1) compare the fat-free mass (FFM) of children with HIV infection with that of control children, 2) assess the contribution of FFM to body weight in HIV-infected children compared with that of control children, and 3) study the relations between body weight, FFM, and mortality. DESIGN: A cross-sectional study was performed in 86 HIV-infected and 113 uninfected children (mean ages: 6.9 and 7.7 y, respectively). FFM was estimated from single-frequency bioelectrical impedance analysis by using 3 different published equations; a further estimate was obtained from triceps-skinfold-thickness measurements. RESULTS: All 4 estimates of body composition showed that FFM in HIV-infected children was significantly less than in control children of similar age. However, FFM as a percentage of body weight was not significantly different between groups. In the whole group of infected children, an age-specific z score < -2 for weight and for FFM was significantly associated with an increased risk of death [relative risk (95% CI) = 11.4 (3.1, 41.0) and 5.1 (1.5, 18.2), respectively]; when only children with more severe disease were considered, only z score for weight was significantly associated with an increased risk [4.6 (1.4, 14.9)]. CONCLUSIONS: These findings suggest that no preferential catabolism of FFM occurs in HIV-infected children and that body weight for age is a better prognostic indicator than is FFM estimated by bioelectrical impedance analysis.     

How pre- and postnatal risk factors modify the effect of rapid weight gain in infancy and early childhood on subsequent fat mass development: results from the Multicenter Allergy Study 90

BACKGROUND: It is unclear which exposures may cause or modify the adverse effect of rapid weight gain on fat mass development in term children whose birth weight is appropriate-for-gestational age (AGA). OBJECTIVE: To determine which intrauterine or postnatal exposures increase the risk of or modify the effect of rapid weight gain on body fat percentage (BF%) and body mass index (BMI) trajectories between 2 and 6 y of age. DESIGN: Term AGA singletons (n = 370) from the German Multicenter Allergy Study (MAS-90), a longitudinal birth cohort study, with repeated anthropometric measurements until 6 y, and data on breastfeeding status, exposure to smoking during pregnancy, and maternal anthropometric and socioeconomic characteristics were included in this analysis. RESULTS: A shorter gestation [multivariate-adjusted odds ratio (OR): 5.12; 95% CI: 2.22, 11.82; P = 0.0001], being firstborn (OR: 2.01; 95% CI: 1.10, 3.69; P = 0.02), and having been bottle-fed (OR: 3.02; 95% CI: 1.68, 5.43; P = 0.0002) all significantly increased a child's risk of gaining weight rapidly, whereas a larger BMI at birth was protective (OR: 0.54; 95% CI: 0.38, 0.77; P = 0.0006). Multilevel model analyses showed that rapid growers exposed to tobacco in utero subsequently gained more BF% between 2 and 6 y than did rapid growers who had not been exposed (beta +/- SE: 0.78 +/- 0.28%/y; P = 0.005). Similarly, change in BF% was greater in rapid growers with an overweight mother than in those with a normal-weight mother (1.01 +/- 0.30%/y; P = 0.0007). CONCLUSIONS: The occurrence of rapid weight gain between birth and 2 y and the magnitude of its effect on BF% development in AGA children is influenced by both intrauterine and postnatal exposures.     

Recovery from relapse among successful weight maintainers

BACKGROUND: Little is known about the natural history of weight change among persons who are successful at losing weight. OBJECTIVE: This study evaluated the occurrence of weight regain and recovery among 2400 persons in the National Weight Control Registry (NWCR) who had lost an average (+/- SD) of 32.1 +/- 17.8 kg and had kept it off for 6.5 +/- 8.1 y. DESIGN: Participants were evaluated prospectively over 2 y. RESULTS: The mean reported weight change from entry into the NWCR to 2 y later was 3.8 +/- 7.6 kg. At year 2, 96.4% of the sample remained > or =10% below their maximum lifetime weight. However, small regains were common, and few persons were able to re-lose weight after any weight regain. Of the participants who gained any weight between baseline and year 1 (n = 1483; 65.7%), only 11.0% returned to their baseline weight or below at year 2. Of the participants who relapsed, which was defined as a weight regain of > or =5% at year 1 (n = 575, or 25.5% of the sample), only 4.7% returned to their baseline weight or below at year 2, and only 12.9% re-lost at least half of their year 1 gain by year 2. Logistic regression showed that recovery was related to gaining less at year 1 and to smaller increases in depressive symptoms between baseline and year 1. CONCLUSION: Although successful weight losers continued to maintain a large percentage of their weight losses over 2 y, recovery from even minor weight regain was uncommon.     

Body size and hip fracture risk. Swedish Hip Fracture Study Group

The objective of this population-based case-control study was to determine the independent association between height, weight at different ages and adult weight change on hip fracture risk, and the joint effects of these factors. The study base comprised postmenopausal women 50-81 years of age who resided in six counties in Sweden during the period October 1993 to February 1995. The study included 1,327 cases with an incident hip fracture and 3,262 randomly selected controls. We obtained information on body measures and other factors possibly related to hip fracture through mailed questionnaires and telephone interviews. Height and weight change were dominant risk factors. Tall women (> or = 169 cm) had an odds ratio of 3.16 (95% confidence interval = 2.47-4.05) compared with women shorter than 159 cm. Weight gain during adult life was strongly protective: compared with those with moderate weight change (-3 to 3 kg), those with substantial weight gain (> or =12 kg) had a markedly decreased risk of hip fracture (odds ratio = 0.35; 95% confidence interval = 0.27-0.45), whereas weight loss was associated with an increased risk. Weight change retained important effects among all subjects, even after controlling for current weight and weight at age 18. In contrast, among women who gained weight, the separate effects of current weight and weight at age 18 were small or absent. Among women who lost weight, both current weight and weight at age 18 had effects that remained after controlling for weight change. Adult weight change and height are dominant body size risk factors for hip fracture. Weight loss vs weight changes demarcates different patterns of hip fracture risk.     

Nutrition status in patients younger and older than 60 y at hospital admission: a controlled population study in 995 subjects

OBJECTIVE: Body weight and body mass index are easily obtainable indicators of nutrition status but do not provide information on changes in fat-free mass (FFM) and fat mass with age. In this prospective controlled study, we investigated whether body composition measurements were useful in identifying moderately or severely depleted patients, as judged by the Subjective Global Assessment at hospital admission. In addition, the subjects were grouped by age (< or =60 and >60 y) to determine whether there was an effect of aging on the prevalence of malnutrition.METHODS: Nine hundred ninety-five consecutive patients were evaluated for malnutrition by body mass index, serum albumin, Subjective Global Assessment, and 50-kHz bioelectrical impedance analysis and compared with 995 age- and height-matched healthy volunteers for FFM and fat mass. RESULTS: A body mass index less than 20 kg/m(2) was found in 17.3% of patients. Low albumin (< or =34.9 g/L) was found in 14.9% of all patients and 23.7% of those older than 60 y. In contrast, 23.1% and 38.3% of all patients were severely and moderately depleted, respectively, according to the Subjective Global Assessment. FFM was significantly lower in severely depleted men and women and moderately depleted women (P < or = 0.001), and fat mass was significantly higher (P < or = 0.05) in well-nourished patients than in volunteers. Patients older than 60 y had lower FFM and higher fat mass than did patients 60 y or younger or volunteers (P < or = 0.001). CONCLUSION: The prevalence of malnutrition was greater in patients older than 60 y than in those 60 y and younger. Patients classified as severely depleted according to the Subjective Global Assessment were depleted of FFM. Body composition measurement can help to identify patients with low FFM and high fat mass.