J Obes Metab Syndr 2019; 28(3): 203-207
Published online September 30, 2019 https://doi.org/10.7570/jomes.2019.28.3.203
Copyright © Korean Society for the Study of Obesity.
College of Science, Engineering and Technology, Grand Canyon University, Phoenix, AZ, USA
Zachary Stephen Zeigler
College of Science, Engineering and Technology, Grand Canyon University, 3300 West Camelback Rd, Phoenix, AZ 85017, USA
Tel: +1-480-200-2416 E-mail: email@example.com
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Weight cycling (WC) is a widespread behavior associated with elevated laboratory blood pressure (BP). The impact WC may have on ambulatory BP (ABP) is unknown. Impact of self-reported WC history on ABP was assessed via cross-sectional nonexperimental design. Sixty-five women completed the Weight and Lifestyle Inventory (WALI) questionnaire. The WALI has been shown to be a reliable index of WC (r=0.87, WC (n=31) were older (39.7±8.9 vs. 33.1±11.3 years), had a higher percent body fat (47.1%±6.2% vs. 41.4%±7.8%), and were less fit (21.2±5.4 vs. 26.7±7.6 mL/kg/min) than NWC (n=34). No significant correlation between laboratory systolic BP (SBP, WC may deleteriously affect BP outcomes that might only be observed when ABP monitoring is used.
Weight cycling (WC) is a widespread behavior associated with elevated laboratory blood pressure (BP). The impact WC may have on ambulatory BP (ABP) is unknown.
Impact of self-reported WC history on ABP was assessed via cross-sectional nonexperimental design. Sixty-five women completed the Weight and Lifestyle Inventory (WALI) questionnaire. The WALI has been shown to be a reliable index of WC (r=0.87,
WC (n=31) were older (39.7±8.9 vs. 33.1±11.3 years), had a higher percent body fat (47.1%±6.2% vs. 41.4%±7.8%), and were less fit (21.2±5.4 vs. 26.7±7.6 mL/kg/min) than NWC (n=34). No significant correlation between laboratory systolic BP (SBP,
WC may deleteriously affect BP outcomes that might only be observed when ABP monitoring is used.
Keywords: Weight, Ambulatory blood pressure, Obesity, Body fat
National surveys have found that roughly 57% of women had been on a weight loss diet in the preceding year.1 Dishearteningly, upwards of 95% of those who lose weight cannot sustain weight loss.2 Thus, dieters relapse into the predictive pattern of weight loss followed by weight regain sequences termed weight cycling (WC). Granted, there is controversy for the topic of WC. However, data shows that WC is related to redistribution of body fat towards increased abdominal adiposity.3 WC has also been highlighted as a contributor of increased blood pressure (BP).4 A 2010 review5 analyzed the available data on the impact of WC on BP in overweight/obese adults. This review found five articles that met inclusion criteria and only one of the five was deemed to be “adequate” quality. Nevertheless, of the five articles, three showed no impact of WC on BP while two showed WC increased BP. The authors determined that there was not enough evidence of acceptable quality to draw definitive conclusions and that additional research is needed for looking at the impact of WC on BP. Surprisingly, none of the involved studies included the superior technique of ambulatory BP (ABP) monitoring.6 To the authors knowledge, there is no data assessing the impact of WC on ABP. Thus, the purpose of this correlational nonexperimental study was to assess ABP differences between WC and non-WC (NWC) overweight/obese woman.
The data for current study was collected in correlation with previous published work assessing the impact of WC on arterial stiffness.7 Sixty-five healthy, overweight/obese, nonsmoking, weight stable, Caucasian women with a body mass index (BMI) >25 kg/m2 and age of 25–60 years were recruited. Subjects did not have diabetes or cardiovascular disease and were not on medication for either. The Grand Canyon University Institutional Review Board approved this study (IRB No. 1087754) and informed consent was obtained prior to enrollment.
Subjects came to the laboratory for a single visit. Anthropometric measures of body weight, height, waist and hip circumferences and body fat (air displacement plethysmography; Bod Pod, Cosmed, Concord, CA, USA) were then measured followed by laboratory BP (Connex ProBP 3400 digital BP device; Welch Allyn, Skaneateles Falls, NY, USA). Next, a peak oxygen uptake (VO2peak) test was completed. VO2peak was defined as the 10 second highest consecutive two points achieved during the exercise test. Subjects were then given the Weight and Lifestyle Inventory (WALI) questionnaire.8 The WALI has been found reliable in reporting number of diets (r=0.77) and amount of weight lost (r=0.87, both
Statistical analyses were performed using IBM SPSS version 24.0 (IBM Corp., Armonk, NY, USA). Statistical analysis included ABP data collected from 09:00 AM to 22:00 PM of the same day. Mean day time ABP between groups were compared using independent t-test. Confounding variables of age, body fat, and VO2peak were then included as covariates via general linear models. Chi-square tests were used to compare frequency differences in BP load (percentage of readings above 140/90 mmHg). Bivariate Pearson correlations were used to assess linear relationships between number of WC’s, as a continuous variable, and systolic and diastolic laboratory BP and mean ABP. Hierarchical regression was used to assess if WC significantly added to the model above what age, body fat, waist-to-hip ratio and VO2peak contribute to predicting BP outcomes.
Sixty-five overweight/obese female subjects completed the study. WC women were older, carried more body fat overall and in the abdominal region, and were not as fit as NWC women (Table 1). Table 1 illustrates that there was no statistical difference in resting (laboratory) systolic BP (SBP) and diastolic BP (DBP) between groups. However, there were statistical differences in mean systolic ABP and diastolic ABP. Because mean group differences were found for age, body fat, waist-to-hip ratio, and VO2peak, these variables were then adjusted for as covariates. Due to collinearity of body fat, BMI, and waist-to-hip ratio, these variables were included alternately. After adjusting for age, there were still differences between groups for systolic ABP (
Because baseline differences in BMI were seen between WC and NWC groups, and since BMI undoubtedly affects B
No significant correlation between laboratory SBP and the number of WC’s was observed (
Fig. 1A shows no statistical difference between WC and NWC on the percentage of SBP readings of <120 or 120–139 mmHg (
To the authors knowledge, this is the first study to assess the possible impact of WC on ABP. The major finding of this investigation was that WC did not affect laboratory BP but may have an impact on daytime ABP, including BP load. This is significant because past literature assessing the impact of WC on BP has been inconclusive possibly due to the method of BP measurement.
Zeigler et al.7 found higher levels of WC were associated with increased laboratory BP values and arterial stiffness, mainly through the mediating impact of increased visceral fat. The current study supports the role of WC on abdominal obesity in that the WC group had a significantly higher waist-to-hip ratio compared to the NWC group. In addition to abdominal obesity, BMI has also been shown to be associated with increased ABP values13 and WC has been shown to be associated with increased BMI.14 When subjects were dichotomized either as WC or NWC and was analyzed by BMI, ABP values were still higher in the WC groups. However, because BMI was still higher in the WC group (39.2±5.2 vs. 35.1± 3.6 kg/m2,
The authors declare no conflict of interest.
We thank the undergraduate research assistants working at the Health Information and Programing Clinic at Grand Canyon University.
Study concept and design: ZSZ; acquisition of data: ZSZ; analysis and interpretation of data: all authors; drafting of the manuscript: all authors; critical revision of the manuscript: all authors; statistical analysis: ZSZ; administrative, technical, or material support: ZSZ; and study supervision: all authors.
|Variable||WC group (n=31)||NWC group (n=34)|
|No. of cycles||5.3±1.8||1.6±1.1||<0.001*|
|Body fat (%)||47.1±6.2||41.4±7.8||0.002*|
|Waist to hip ratio||0.83±0.12||0.71±0.23||0.015*|
|Resting SBP (mmHg)||126.5±14.1||123.5±11.3||0.499|
|Resting DBP (mmHg)||77.7±10.3||76.2±7.1||0.525|
|Ambulatory SBP (mmHg)||130.1±13.6||122.0±8.2||0.006*|
|Ambulatory DBP (mmHg)||76.2±8.9||70.0±9.0||0.011*|
WC, weight cycling; NWC, non-WC; BMI, body mass index; VO2peak, peak oxygen uptake; SBP, systolic blood pressure; DBP, diastolic blood pressure.