Abstract: The fundamental cause of metabolic syndrome is thought to be abdominal obesity. Accurate diagnosis of abdominal obesity can be done by an x-ray computed tomography (CT) scan. But CT is expensive, bulky and entails the risks involved with radiation. To overcome such disadvantages, we attempted to develop a measuring device that could apply electrical impedance tomography to abdominal fat imaging. The device has 32 electrodes that can be attached to a subject's abdomen by a pneumatic mechanism. That way, electrode position data can be acquired simultaneously. An applied alternating current of 1.0 mArms was used at a frequency of 500 kHz. Sensed voltage data were carefully filtered to remove noise and processed to satisfy the reciprocal theorem. The image reconstruction software was developed concurrently, applying standard finite element methods and the Marquardt method to solve the mathematical inverse problem. The results of preliminary experiments showed that abdominal subcutaneous fat and the muscle surrounding the viscera could be imaged in humans. While our imaging of visceral fat was not of sufficient quality, it was suggested that we will be able to develop a safe and practical abdominal fat scanner through future improvements.
Abstract: OBJECTIVE: The objective of this study was to investigate the effect of 1-year ad libitum consumption of diacylglycerol oil on body weight and serum triglyceride in Japanese men and women. DESIGN/SUBJECTS/INTERVENTION: In a 1-year double-blind, placebo-controlled parallel trial with clinic visits at month 0, 3, 6, 9, and 12, a total of 312 Japanese men (n=174) and women (n=138) (aged 22 to 73 years) with body mass index (calculated as kg/m(2)) > or =25 and/or fasting serum triglyceride level > or =150 mg/dL (1.70 mmol/L) (aged 22 to 73 years) were randomly assigned to the diacylglycerol (n=155) or triacylglycerol (n=157) group. Participants substituted their usual home cooking oil with the assigned test oils. MAIN OUTCOME MEASURES: Changes in anthropometrics and serum triglyceride level were monitored at 3-month intervals across a 12-month period. RESULTS: In the intention-to-treat analysis, body weight decreased significantly in the diacylglycerol group when compared to the triacylglycerol group (P=0.013). Changes in body weight and body mass index during the study period differed between the two groups by 0.87 kg (P=0.002) and 0.32 kg (P=0.002), respectively. Participants with higher initial body mass index or greater percentage of total fat intake as diacylglycerol exhibited greater reduction in body weight. Total energy intake and physical activity were not significantly different between the groups during the study. Serum triglyceride levels decreased significantly from values in individuals with hypertriglyceridemia, but did not differ between groups. CONCLUSIONS: Modest body weight reduction was observed after 1-year ad libitum consumption of diacylglycerol oil as part of a regular diet in comparison to that of triacylglycerol oil; weight loss was greatest in participants who were obese at baseline. The weight reduction observed in diacylglycerol group was attributed to the substitution of usual home cooking oil with diacylglycerol, because total energy intake and physical activity did not differ between groups.
Abstract: Several studies in animals and humans have reported beneficial effects of diacylglycerol (DAG) on lipid and energy metabolism. We assessed the effect of DAG versus triacylglycerol (TAG) treatment on total energy expenditure (TEE), total fat oxidation (Fox) and respiratory quotient (RQ), and measured the oxidation rate of each oil using a respiratory chamber and the (13)C-stable isotope. Eleven healthy subjects participated in a double-blind, randomized crossover study. Subjects consumed an energy maintenance diet consisting of 55% of total calories from carbohydrate, 15% from protein and 30% from fat during both the 3-day pre-chamber and 36-h chamber period. Fifty percent of the fat was test oil, containing either DAG oil or TAG oil. The oxidation rate of ingested test oils was determined by monitoring (13)CO(2) excretion in the breath from (13)C-labeled diolein or (13)C-labeled triolein. There were no significant differences in TEE, RQ and total Fox between the DAG and TAG treatment in the overall analysis. In the subgroup analysis, DAG treatment decreased RQ significantly in subjects with a high fat ratio (HFR) compared to TAG treatment. In addition, ingested diolein oxidation in DAG treatment was significantly faster than triolein oxidation in TAG treatment in the HFR group. Enhanced fat utilization with DAG treatment and rapid oxidation of ingested DAG may, at least in part, explain the greater loss of body weight and body fat related to DAG consumption found in the weight-loss studies.
Abstract: BACKGROUND: Several studies have reported increased fat oxidation with diacylglycerol (DAG) oil consumption. However, the effects of long-term DAG oil consumption on energy metabolism remain to be investigated. OBJECTIVE: The objective of this study was to compare the effects of 14 days of either DAG or triacylglycerol (TAG) oil consumption on substrate oxidation, energy expenditure (EE) and dietary fat oxidation. DESIGN: Eight males and six females participated in this randomized, double-blind, crossover feeding study. Each patient consumed the 14-day controlled test diet containing either 10 g day(-1) of DAG or TAG oil for acclimatization before a respiratory chamber measurement, followed by a 2-week washout period between diet treatments. Substrate oxidation and EE were measured in the respiratory chamber at the end of each dietary treatment. The patients consumed test oil as 15% of total caloric intake in the respiratory chamber (mean test oil intake was 36.1+/-6.6 g day(-1)). RESULTS: Twenty-four hour fat oxidation was significantly greater with 14 days of DAG oil consumption compared with TAG oil consumption (78.6+/-19.6 and 72.6+/-14.9 g day(-1), respectively, P<0.05). There were no differences in body weight or body composition between diet treatments. Dietary fat oxidation was determined using the recovery rate of (13)CO(2) in breath, and was significantly enhanced with DAG oil consumption compared with TAG oil consumption, measured over 22 h after ingestion of (13)C-labelled triolein. Resting metabolic rate (RMR) was significantly greater with DAG oil consumption compared with TAG oil consumption (1766+/-337 and 1680+/-316 kcal day(-1), respectively, P<0.05). CONCLUSION: Consumption of DAG oil for 14 days stimulates both fat oxidation and RMR compared with TAG oil consumption, which may explain the greater loss of body weight and body fat with DAG oil consumption that has been observed in weight-loss studies.
Abstract: BACKGROUND AND AIM: Coffee is rich in chlorogenic acids (CGA), whose metabolites may have beneficial effects such as anti-hypertensive effects. However, trial results concerning the effects of coffee on blood pressure (BP) are not consistent. A recent study suggested that hydroxyhydroquinone (HHQ), produced by the roasting of green coffee beans, inhibits the effect of CGA. In the present study, the dose-response for CGA in HHQ-free coffee on BP were investigated in mildly hypertensive men and women. METHODS AND RESULTS: The trial design was a double-blind, randomized controlled trial, with five study groups including, control, zero-dose, low-dose, middle-dose and high-dose. The control beverage was identical to ordinary coffee. The others contained reduced HHQ levels, compared to ordinary coffee, and the CGA were adjusted in target concentration. A total of 203 subjects were randomly allocated. Each subject drank one cup of coffee per day. The study involved a screening and a baseline observation period of 6 weeks and an intervention period of 4 weeks. BP response showed CGA has an anti-hypertensive effect in a dose-dependent manner in HHQ-free coffee, and ordinary coffee showed almost no effect. As a result, a significant correlation between BP change and the three dose-response patterns was observed (p<0.001). CONCLUSIONS: This study demonstrates a dose-dependent decrease in BP for CGA in HHQ-free coffee.
