Fat-free mass index: changes and race/ethnic differences in adulthood.

OBJECTIVE: Nutritional status is assessed by measuring BMI or percent body fat (%fat). BMI can misclassify persons who carry more weight as fat-free mass and %fat can be misleading in cases of malnutrition or in disease states characterized by wasting of lean tissue. The fat-free mass index (FFMI) is proposed to assess body composition in individuals who have a similar body composition but differ in height allowing identification of those suffering from malnutrition, wasting or those that possess a relatively high muscle mass. The purpose was to determine whether the FFMI differs in a group of racially/ethnically diverse adults. DESIGN: Cross-sectional. SUBJECTS: Subjects were a multi-ethnic sample (Caucasian, CA; African American, AA; Hispanic, HIS and Asian, AS) of 1339 healthy males (n = 480) and females (n = 859) ranging in age from 18-110 years. Total body fat, total fat-free mass and bone mineral density were estimated using dual energy X-ray absorptiometry. RESULTS: FFMI differed among the four ethnic groups (P ≤ 0.05) for both genders. A curvilinear relationship was found between age and FFMI for both genders although the coefficients in the quadratic model differed between genders (P ≤ 0.001) indicating the rate of change in FFMI differed between genders. The estimated turning point where FFMI started to decline was in the mid 20s for male and mid 40s for female participants. An age × gender interaction was found such that the rate of decline was greater in male than female participants (P ≤ 0.001). For both genders, FFMI was greatest in AA and the least in AS (P ≤ 0.001). There was no significant interaction between race and age or age(2) (P = 0.06). However, male participants consistently had a greater FFMI than female participants (P ≤ 0.001). CONCLUSIONS: These findings have clinical implications for identifying individuals who may not be recognized as being malnourished based on their BMI or %fat but whose fat-free mass corrected for height is relatively low.

Treatment of Parkinson disease with diet-induced hyperketonemia: a feasibility study.

Ketones may bypass the defect in complex I activity implicated in Parkinson disease (PD). Five of seven volunteers with PD were able to prepare a "hyperketogenic" diet at home and adhere to it for 28 days. Substituting unsaturated for saturated fats appeared to prevent cholesterol increases in four volunteers. Unified Parkinson's Disease Rating Scale scores improved in all five during hyperketonemia, but a placebo effect was not ruled out.

Annual deaths attributable to obesity in the United States.

CONTEXT: Obesity is a major health problem in the United States, but the number of obesity-attributable deaths has not been rigorously estimated. OBJECTIVE: To estimate the number of deaths, annually, attributable to obesity among US adults. DESIGN: Data from 5 prospective cohort studies (the Alameda Community Health Study, the Framingham Heart Study, the Tecumseh Community Health Study, the American Cancer Society Cancer Prevention Study I, and the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study) and 1 published study (the Nurses' Health Study) in conjunction with 1991 national statistics on body mass index distributions, population size, and overall deaths. SUBJECTS: Adults, 18 years or older in 1991, classified by body mass index (kg/m2) as overweight (25-30), obese (30-35), and severely obese (>35). MAIN OUTCOME MEASURE: Relative hazard ratio (HR) of death for obese or overweight persons. RESULTS: The estimated number of annual deaths attributable to obesity varied with the cohort used to calculate the HRs, but findings were consistent overall. More than 80% of the estimated obesity-attributable deaths occurred among individuals with a body mass index of more than 30 kg/m2. When HRs were estimated for all eligible subjects from all 6 studies, the mean estimate of deaths attributable to obesity in the United States was 280184 (range, 236111-341153). Hazard ratios also were calculated from data for nonsmokers or never-smokers only. When these HRs were applied to the entire population (assuming the HR applied to all individuals), the mean estimate for obesity-attributable death was 324 940 (range, 262541-383410). CONCLUSIONS: The estimated number of annual deaths attributable to obesity among US adults is approximately 280000 based on HRs from all subjects and 325000 based on HRs from only nonsmokers and never-smokers.

Weight loss increases and fat loss decreases all-cause mortality rate: results from two independent cohort studies.

OBJECTIVE: In epidemiological studies, weight loss is usually associated with increased mortality rate. Contrarily, among obese people, weight loss reduces other risk factors for disease and death. We hypothesised that this paradox could exist because weight is used as an implicit adiposity index. No study has considered the independent effects of weight loss and fat loss on mortality rate. We studied mortality rate as a function of weight loss and fat loss. DESIGN: Analysis of 'time to death' in two prospective population-based cohort studies, the Tecumseh Community Health Study (1890 subjects; 321 deaths within 16y of follow-up) and the Framingham Heart Study (2731 subjects; 507 deaths within 8y of follow-up), in which weight and fat (via skinfolds) loss were assessable. RESULTS: In both studies, regardless of the statistical approach, weight loss was associated with an increased, and fat loss with a decreased, mortality rate (P < 0.05). Each standard deviation (s.d.) of weight loss (4.6 kg in Tecumseh, 6.7 kg in Framingham) was estimated to increase the hazard rate by 29% (95% confidence interval CI), (14%, 47%, respectively) and 39% (95% CI, 25%, 54% respectively), in the two samples. Contrarily, each s.d. of fat loss (10.0 mm in Tecumseh, 4.8 mm in Framingham) was estimated to reduce the hazard rate 15% (95% CI, 4%, 25%) and 17% (95% CI, 8%, 25%) in Tecumseh and Framingham, respectively. Generalisability of these results to severely (that is, body mass index BMI) > or = 34) obese individuals is unclear. CONCLUSIONS: Among individuals that are not severely obese, weight loss is associated with increased mortality rate and fat loss with decreased mortality rate.

Prevalence of obesity.

Numerical values for prevalence of obesity are highly dependent on the criteria used to identify the condition and its gradations of severity. Prevalence is also affected by the makeup of the surveyed population. Recently, national surveys of prevalence of obesity in the United States and some European countries have been reported in terms of criteria that permit direct comparison of the findings. When the prevalence of a body mass index is 30 kg/m2 or more in US adults is compared with findings in adults in the United Kingdom, France, the Netherlands, and Italy, the differences are striking, with prevalence ratios ranging from approximately 1.5 (US versus UK) to 3.0 (US versus France).

Worldwide epidemiology of obesity.

Average body mass index values and prevalence data for overweight show complex patterns varying with sex, age, socioeconomic circumstances, race, geography, and over time. Differences in the predominant lifestyles and developmental status of nations and regions also influence weight patterns. Estimates of the prevalence of obesity in developed countries vary depending on the definitions used. For example, one recent survey has reported that the prevalence of obesity in the US is 15%, while another survey has found it to be 26%. It appears that overweight and obesity are becoming more prevalent worldwide, not only in developed nations, but also in the populations of developing countries, possibly as a result of urbanisation, migration, new eating habits and recent affluence. Since modernisation appears to be an inevitable process throughout the world, there is every reason to expect that the epidemic of overweight and obesity will extend globally in the future.

Clinical correlates of short- and long-term weight loss.

This study was designed to identify psychological, behavioral, and physiological correlates of short- and long-term weight loss. Measures of psychological functioning, body composition, fat cell size and number, and attendance were evaluated in 76 obese women for their relationship to weight loss at the end of treatment and at a 1-y follow-up evaluation. Losing more weight during the first month of treatment and attending a higher percentage of treatment sessions were strongly associated with greater weight loss at the end of treatment and at 1-y follow-up. In addition, patients with the highest initial weights lost the most weight both at the end of treatment and at 1-y follow-up. Easily obtained measures are as successful in predicting weight loss as are more expensive and complicated measures.

Height-normalized indices of the body's fat-free mass and fat mass: potentially useful indicators of nutritional status.

Expressing fat-free mass (FFM) and body fat mass (BFM) as percentages of body weight or by weight is unsatisfactory. For example, tall patients with protein-energy malnutrition (PEM) can exhibit values for FFM and BFM similar to those of shorter well-nourished individuals. To obviate such difficulties, we propose use of height-normalized indices, namely, a FFM index [FFM (kg)/height (m)2, or FFMI] and a BFM index [BFM (kg)/height (m)2, or BFMI]. We calculated these indices in a reference population of 124 healthy young men and in 32 nonobese young men (from the Minnesota Study) before, during, and after experimental semistarvation. When values for FFMI and BFMI falling below the reference cohort's 5th percentile cutoff point were used as a criterion for PEM, these indices, together with basal oxygen-consumption rate, diagnosed PEM in 27 of the 32 Minnesota Study subjects after 12 wk of semi-starvation. These findings indicate that FFMI and BFMI may be useful in nutritional assessment.

Rats enriched with odd-carbon fatty acids: maintenance of liver glycogen during starvation.

In young rats a diet containing triundecanoin as the major source of fat produces substantial enrichment of adipose tissue triglycerides with undecanoate and higher fatty acids with odd-numbered carbons. The terminal three-carbon residues arising from beta-oxidation of these acids are glucogenic and help to counteract the decreases in liver glycogen and serum glucose ordinarily induced by prolonged fasting.