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
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37898 |
| Date | 28 March 2014 |
| Creators | Pilolla, Kari D. |
| Contributors | Manore, Melinda |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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