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Changes in body composition and metabolic syndrome risk factors : response to energy-restriction, protein intake, and high intensity interval training

Metabolic syndrome (MetS) and abdominal obesity (AbOb) increase the risk of
developing cardiovascular disease and diabetes. Energy restriction (ER), highprotein
(PRO) intake and high-intensity interval training (HIT) can independently
improve MetS and AbOb. However, ER reduces metabolically active lean body
mass (LBM) in addition to body fat (BF). Purpose: To determine the effects of a
16-wk ER diet with 2 levels of PRO (15% or 25% of energy), plus HIT, on MetS
risk factors, AbOb, and body composition in women. Methods: Sedentary,
premenopausal women (age=35±10y) with AbOb (waist circumference [WC]
≥80cm) were randomized to a 16-wk ER diet (-300kcals/d) with 15% (15PRO;
n=17) or 25% (25PRO; n=18) of energy from PRO, plus 45min/d, 3d/wk HIT and
45min/d, 2d/wk continuous moderate-intensity exercise (CME) (-200kcals/d). Diet
and physical activity (PA) were assessed using 4-d weighed food and PA
records, respectively; diet and exercise compliance were assessed monthly with
multiple-pass 24-h recalls and weekly tracking logs. Body weight (BW), WC,
DXA-assessed body composition (BF [%], BF [kg], trunk fat [kg], and LBM [kg]),
blood lipids (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C],
low-density lipoprotein cholesterol [LDL-C], triglycerides [TG]), glycemic markers
(fasting plasma glucose [FPG], insulin, and homeostatic model assessment for
insulin resistance [HOMA-IR], beta cell function [HOMA-%β] and insulin
sensitivity [HOMA-%S]) and resting blood pressure (BP) (systolic BP [SBP];
diastolic BP [DBP]) were assessed pre/post-intervention. Repeated measures
analysis of variance and two sample t-tests were used at analyze the date.
Results are reported as means±standard deviations. Results: There were
significant time, but not group, differences in BW (-5.1±2.6kg, p=0.0141), WC (-
7.3±3.6cm, p<0.0001), TC (-18.1±17.4mg/dL, p<0.0001), LDL-C (12.2±
16.2mg/dL, p<0.0001), TG (-25.3±56.2mg/dL, p=0.0064), insulin (-2.1±4.2mg/dL,
p=0.0048), HOMA-IR (-0.2±0.5, p=0.0062), HOMA-%β (-12.1±35.2%, p=0.0497),
HOMA-%S (28.5±78.4%, p=0.0357), and SBP (-3±9mmHg, p=0.214). There
were significant group x time differences in DBP (15PRO=-5±8mmHg, 25PRO=-
2±8mmHg; p=0.0024). There were no time or group differences in FPG or HDLC.
There were significant time, but not group, effects on changes in BW (-5.1kg±
2.6, p<0.0001), BF (-3.3±1.6%, p<0.0001), and LBM (-0.6kg±1.5, p=0.0283). The
15PRO group lost more absolute whole BF (-5.2kg vs. -3.9kg, p=0.0355) and
trunk fat (-3.1kg vs. -2.2kg) vs. the 25PRO group. Conclusion: Both diets
significantly improved BW, AbOb, MetS risk factors, glycemic control, and BF
(%); LBM (kg) loss was similar in both groups. Compared to the 15PRO diet had
significantly greater absolute BF-kg and trunk fat-kg losses. Increased PRO
intake did not improve AbOb or MetS risk beyond ER and HIT/CME. The impact
of HIT/CME and the greater (-1.3kg) changes in BW in the 15PRO group may
have contributed significantly to the changes in absolute BF and trunk fat. More
research is needed to separate the impact of HIT/CME and weight loss from the
impact of PRO during ER. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 28, 2013 - March 28, 2014

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37898
Date28 March 2014
CreatorsPilolla, Kari D.
ContributorsManore, Melinda
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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