Moderate Weight Loss Improves Body Composition and Metabolic Function in Metabolically Unhealthy Lean Subjects.

OBJECTIVE: Individuals who have "metabolically obese normal weight" (MONW) have an increased risk for cardiometabolic disease. Moderate weight loss has multiple benefits in people with obesity, but its effects in lean people are unknown. Thus, the effects of diet-induced 5% weight loss on body composition and metabolic function in MONW subjects were evaluated. METHODS: Total body fat, visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAT) volumes, intrahepatic and intramyocellular lipid contents, insulin sensitivity (hyperinsulinemic-euglycemic clamp), glucose tolerance, and postprandial insulin secretion and clearance rates (mixed meal with minimal modeling) were measured before and after 4.8% ± 0.5% weight loss in 11 MONW Asians (48 ± 3 years old, six men and five women, BMI 22.7 ± 0.4 kg/m2 ). RESULTS: Weight loss decreased total fat mass by ∼9%, VAT and SAT volumes by ∼11% and ∼17%, respectively, and intrahepatic fat by ∼50% (all P < 0.05). Fasting plasma insulin, triglyceride, and total low- and high-density lipoprotein cholesterol concentrations were also reduced (P < 0.05). Insulin sensitivity indexes (M-value and M/I ratio) increased by 21% to 26% (both P < 0.05); ß-cell responsivity and postprandial insulin secretion rate did not change, but insulin clearance rate increased by 16% (P < 0.05). CONCLUSIONS: Diet-induced moderate weight loss improves body composition, lipid profile, and insulin sensitivity and thereby reduces cardiometabolic risk in MONW Asians.

Phase transformation of molecular beam epitaxy-grown nanometer-thick Gd2O3 and Y2O3 on GaN.

High quality nanometer-thick Gd2O3 and Y2O3 (rare-earth oxide, R2O3) films have been epitaxially grown on GaN (0001) substrate by molecular beam epitaxy (MBE). The R2O3 epi-layers exhibit remarkable thermal stability at 1100 °C, uniformity, and highly structural perfection. Structural investigation was carried out by in situ reflection high energy electron diffraction (RHEED) and ex-situ X-ray diffraction (XRD) with synchrotron radiation. In the initial stage of epitaxial growth, the R2O3 layers have a hexagonal phase with the epitaxial relationship of R2O3 (0001)(H)<1120>(H)//GaN(0001)(H)<1120>(H). With the increase in R2O3 film thickness, the structure of the R2O3 films changes from single domain hexagonal phase to monoclinic phase with six different rotational domains, following the R2O3 (201)(M)[020](M)//GaN(0001)(H)<1120>(H) orientational relationship. The structural details and fingerprints of hexagonal and monoclinic phase Gd2O3 films have also been examined by using electron energy loss spectroscopy (EELS). Approximate 3-4 nm is the critical thickness for the structural phase transition depending on the composing rare earth element.