Physical activity and fat-free mass during growth and in later life

BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass.OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age.METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution.RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males &lt; 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants &lt; 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively.CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.</p

No effects of Korean pine nut triacylglycerol on satiety and energy intake

<p>Abstract</p> <p>Background</p> <p>Triacylglycerols (TAG) have been shown to have potential appetite suppressing effects. This study examined the effects of 3 g and 6 g Korean pine nut triacylglycerols (PinnoThin) on appetite and energy intake.</p> <p>Methods</p> <p>130 g Isoenergetic yogurt containing either placebo (milk fat) or PinnoThin TAG was consumed as a breakfast, after an overnight fast, in a double blind randomized crossover design. Appetite profile ratings were determined by visual analogue scale at regular intervals for a period of 4 h after the breakfast. In phase I, 6 g PinnoThin TAG and placebo was tested in thirty-three healthy women (mean ± SD, BMI 26.4 ± 3.8 kg/m²; age 28 ± 10 y) to determine the appetite suppressing effect in time. In phase II, an additional dose of 3 g PinnoThin TAG, as well as 6 g PinnoThin TAG and placebo, was tested in thirty-four women (BMI 25.8 ± 2.9 kg/m²; age 25 ± 9 y) to determine energy intake from an <it>ad libitum </it>lunch offered at 210 min after the breakfast, at which maximal differences in appetite profile ratings were present in phase I.</p> <p>Results</p> <p>Area under the curve of appetite profile ratings was not significantly different between the conditions. Energy intake was 9.5% lower after 6 g PinnoThin TAG compared with 3 g PinnoThin TAG, but there was no significant difference with the placebo.</p> <p>Conclusion</p> <p>A dosage of 6 g PinnoThin TAG is not sufficient to suppress appetite and energy intake.</p> <p>Trial registration</p> <p>Clinical Trials <a href="http://www.clinicaltrials.gov/ct2/show/NCT01034605">NCT01034605</a></p

Residence time distribution and hold-up in a cocurrent upflow packed bed reactor at elevated pressure

The residence time distribution in liquid phase was measured in a cocurrent upflow packed bed reactor for the system methanol-hydrogen at low Reynolds numbers and at elevated pressure. The plug flow with axial dispersion model was used to describe mixing in the system. The imperfect pulse method was used to measure the system response to a tracer pulse input. The parameters were calculated using the weighted moments method. The influence of the weighting factor was investigated. The experimental and theoretical outputs, as calculated by convolution, agreed very well. Different types of correlations were used for the Bodenstein number and liquid hold-up. From these correlations, the optimal one was selected for each parameter. A comparison was made between the ordinary moments and the weighted moments methods which led to the conclusion that the latter method is superior with respect to the accuracy of the estimated parameters and therefore strongly recommended

How rats economize:Energy loss in starvation

The present study is a contribution to the further analysis of the problem of adaptation of energy expenditure to uptake. Clearly, this can not be solved by the study of total metabolic rate alone, but only by an analysis of the various components that make up this total. ... Zie: General introduction

Physical activity and fat-free mass during growth and in later life

BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age. METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution. RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males \u3c 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants \u3c 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively. CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults