Michelle Alencar

Time course of supine and standing shifts in total body, intracellular and extracellular water for a sample of healthy adults

Background/objectives:Traditional tetrapolar bioimpedance spectroscopy (BIS) is performed with the participant supine for 10 min. New vertical analyzers are penetrating clinical, home and fitness markets, but have body water values that differ from supine reference measures. The minimum time standing prior to assessment does not appear in the literature. We investigated the time course of body water shifts in healthy adults undergoing 30-min assessments in supine and vertical positions.Subjects/methods:While seated, participants were prepped for standard tetrapolar electrode placement. Starting position was counterbalanced and body water measurements were taken every 5 min for 30 min in both positions. Participants sat for 2 min prior to switching positions. Of the 64 participants, three were unable to stand for 30 min; their data were excluded. Body size differences were minimized via computation of relative (%) change between time intervals for total body water (TBW), extracellular water (ECW) and intracellular water (ICW).Results:ECW and ICW shifted in opposite directions while participants were supine; as ECW decreased at each time point, ICW increased (P<0.0125). Likewise, when participants stood, ECW increased incrementally (P<0.0125), but the decreases in ICW were not significant. At each time interval, the changes in supine ECW and ICW differed from the standing values (P<0.05). No postural or time differences were found for %change TBW.Conclusions:For TBW, 5 min appears sufficient for fluid stabilization in either position. Supine ECW and ICW stabilization require more than 30 min as does standing ECW.

Increased meal frequency attenuates fat-free mass losses and some markers of health status with a portion-controlled weight loss diet

Increased meal frequency (MF) may be associated with improvements in blood markers of health and body composition during weight loss; however, this claim has not been validated. The purpose of the study was to determine if either a 2-meal (2 MF) or 6-meal frequency (6 MF) regimen can improve body composition and blood-based markers of health while consuming a portion-controlled equihypocaloric diet. Eleven (N=11) obese women (52 ± 7 years, 101.7 ± 22.6 kg, 39.1 ± 7.6 kg/m(2)) were randomized into treatment condition (2 MF or 6 MF) for 2 weeks, completed a 2-week washout, and alternated treatment conditions. In pre/post fashion, changes in body composition, glucose, insulin, and lipid components were measured in response to a test meal. Body mass was successfully lost (P ≤ .05) under both feeding regimens (2 MF: -2.8 ± 1.5 vs 6 MF: -1.9 ± 1.5 kg). Altering MF did not impact glucose, insulin, total cholesterol, or low-density lipoprotein cholesterol (P>.05). On average, fat-free mass (FFM) decreased by -3.3% ± 2.6% following the 2 MF condition and, on average, increased by 1.2% ± 1.7% following the 6 MF condition (P ≤ .05). Fasting high-density lipoprotein cholesterol (HDL-C) percentage increased during the 2 MF condition; this was significantly greater than that in the 6 MF condition (1.3% ± 12.2% vs 0.12% ± 10.3%) (P ≤ .05). Overall, reductions in MF (2 MF) were associated with improved HDL-C levels; but the clinical significance is not clear. Alternatively, increased MF (6 MF) did appear to favorably preserve FFM during weight loss. In conclusion, caloric restriction was effective in reducing body mass and attenuating FFM changes in body composition; however, glucose, insulin, and lipid metabolism had no significant differences between MF.

The efficacy of a telemedicine-based weight loss program with video conference health coaching support:

Introduction Clinically significant weight loss is defined as a ≥5% of initial body weight loss within a 6-month period. The purpose of this study was to assess body weight change from a 12-week telehealth-based weight loss program that integrated health coaching via video conferencing. Methods A total of 25 obese participants (12 males, 13 females) were recruited for this fully online 12-week weight loss program. Participants were randomly assigned to either an intervention group or control group (n = 13 intervention, body mass index (BMI) = 34.7 ± 4.5 kg/m2; n = 12 control, BMI = 34.4 ± 4.43 kg/m2). All participants were given access to a secure platform for data tracking and video conferencing with the research team. The intervention group met with the medical doctor once per month and with a registered dietitian, weekly. Control participants met with the research team at baseline and at 12 weeks. Independent samples t-tests and Chi-square tests were used via SPSS version 24 with significance set to p < 0.05. Results There was a significant difference between the intervention and control groups for body weight loss (7.3 ± 5.2 versus 1.2 ± 3.9 kg, respectively, p < 0.05) as well as for percent body weight loss (7.16 ± 4.4 versus 1.5 ± 4.1%, respectively, p < 0.05). Clinically significant weight loss was achieved in 9 out of 13 (69.2%) in the intervention group versus 1 out of 12 (8%) in the control group. Discussion Mobile phone-based health coaching may promote weight loss. Weekly video conferencing with education may be an applicable tool for inducing significant body weight loss in obese individuals.