Mitsuhiro Katashima

Nighttime snacking reduces whole body fat oxidation and increases LDL cholesterol in healthy young women

The increase in obesity and lipid disorders in industrialized countries may be due to irregular eating patterns. Few studies have investigated the effects of nighttime snacking on energy metabolism. We examined the effects of nighttime snacking for 13 days on energy metabolism. Eleven healthy women (means ± SD; age: 23 ± 1 yr; body mass index: 20.6 ± 2.6 kg/m(2)) participated in this randomized crossover trial for a 13-day intervention period. Subjects consumed a specified snack (192.4 ± 18.3 kcal) either during the daytime (10:00) or the night time (23:00) for 13 days. On day 14, energy metabolism was measured in a respiratory chamber without snack consumption. An oral glucose tolerance test was performed on day 15. Relative to daytime snacking, nighttime snacking significantly decreased fat oxidation (daytime snacking: 52.0 ± 13.6 g/day; nighttime snacking: 45.8 ± 14.0 g/day; P = 0.02) and tended to increase the respiratory quotient (daytime snacking: 0.878 ± 0.022; nighttime snacking: 0.888 ± 0.021; P = 0.09). The frequency of snack intake and energy intake, body weight, and energy expenditure were not affected. Total and low-density lipoprotein (LDL) cholesterol significantly increased after nighttime snacking (152 ± 26 mg/dl and 161 ± 29 mg/dl; P = 0.03 and 76 ± 20 mg/dl and 83 ± 24 mg/dl; P = 0.01, respectively), but glucose and insulin levels after the glucose load were not affected. Nighttime snacking increased total and LDL cholesterol and reduced fat oxidation, suggesting that eating at night changes fat metabolism and increases the risk of obesity.

Visceral Fat Area, Waist Circumference and Metabolic Risk Factors in Abdominally Obese Chinese Adults

OBJECTIVE To examine the association of visceral adiposity as measured by VFA and WC with lipid and glucose metabolic biomarkers in abdominally obese Chinese adults, and to assess whether WC could be an indicator of visceral fat. METHODS WC and VFA were measured in 155 overweight and obese adults. A fasting blood sample was collected from participant (n = 118) whose VFA > or = 100 cm2 for analyses of lipid and glucose profile. The relationship between VFA and WC and biomarkers was investigated. RESULTS WC and VFA were significantly interrelated. The coincidence rate of abdominal obesity determined by Japanese VFA and Chinese WC criteria increased across age quartiles in women from 51.7% to 96.2%. A large WC was associated significantly with low HDL-cholesterol concentration (P < 0.01) and the association was weakened by additional control of VFA. WC and VFA were positively associated with glucose, hemoglobin A1c and insulin concentrations (P < 0.05 except for the association of VFA with insulin: P < 0.01), and all the associations were not significant by additional control of either WC or VFA. As WC quartiles increased, significant stepwise increments in triglyceride, glucose, hemoglobin A1c and insulin and descent in HDL-cholesterol were observed. However, triglyceride and HDL-cholesterol were not significantly different when compared across VFA quartiles. CONCLUSION Higher visceral fat was associated with an adverse lipid and glucose profile. WC can be a moderate predictor for visceral fat and provides a feasible measurement to estimate glucose metabolic risks. Further studies are warranted to establish age-specific WC cutoffs.

The short-term effect of diacylglycerol oil consumption on total and dietary fat utilization in overweight women.

Diacylglycerol (DAG) is a natural component of edible oils with metabolic characteristics distinct from those of triacylglycerol (TAG). Consumption of DAG oil (containing >80% DAG) induces greater fat oxidation than consumption of TAG oil. We compared the effects of 4 days of DAG oil consumption with those of TAG oil consumption on total and dietary fat oxidation over 24 h in overweight women using a whole‐room respiratory chamber. Overweight (BMI (kg/m2) ≥25) females participated in this double‐blind, crossover‐controlled trial. The subjects consumed test diets containing either TAG or DAG oil as 15% of their total caloric intake (mean test oil intake was 33.0 ± 3.1 g/day) during each 4‐day treatment. Fat oxidation and energy expenditure were measured in a respiratory chamber on the 4th day of each treatment. Compared with TAG oil, DAG oil consumption significantly increased total fat oxidation and dietary fat oxidation in overweight subjects. Total energy expenditure (TEE) and carbohydrate (CHO) oxidation did not significantly differ between DAG oil and TAG oil consumption in overweight subjects. Compared with TAG oil, DAG oil consumption enhanced total fat oxidation and dietary fat oxidation in overweight subjects. The enhanced fat metabolism in overweight subjects that consumed DAG oil partly explains the greater loss of body weight and body fat related to DAG oil consumption in weight‐loss studies.

Association of dietary factors with abdominal subcutaneous and visceral adiposity in Japanese men

OBJECTIVE The aim of this study was to assess the relationship between dietary factors and abdominal subcutaneous and visceral adipose tissue in overweight and obese men. METHODS A pooled cross-sectional analysis was conducted to evaluate the associations between dietary factors (nutrition, dietary pattern and alcohol consumption) and subcutaneous fat area (SFA) and visceral fat area (VFA) in 301 Japanese men, aged 21-65 years. RESULTS The standardized regression coefficients of major dietary items (total energy intake, energy intake from breakfast, lunch, supper, between-meal, protein, fat, carbohydrate and alcohol) were positive for VFA in multiple linear regression analyses with the use of age and dietary items as independent variables. The energy intake from between-meal snacks correlated with SFA (standardized regression coefficient β = 0.174, p = 0.002). The coefficient of alcohol intake was positive for VFA and negative for SFA, and alcohol intake correlated with the VFA/total fat area (TFA) ratio (β = 0.130, p = 0.009). Alcohol intake was positively correlated with the blood non-esterified fatty acid concentration. Alcohol consumption additively increased energy intake from supper. The risk of an increase to VFA ≥ 100 cm(2) was 2.02 times higher (95% CI: 1.15, 3.56) for subjects whose energy intake was ≥ 2200 kcal/d, and 2.07 times higher (95% CI: 1.26, 3.42) in those who consumed ≥ 3 g/d alcohol. The risk of an increase to a VFA/TFA ratio ≥ 0.4 was 1.81 times higher (95% CI: 1.01, 3.23) for subjects whose energy intake from supper was ≥ 1000 kcal/d. CONCLUSION Our results indicate that habitual alcohol drinking and high-energy intake from supper are associated with disproportionate accumulation of visceral fat.

Effect of shortened sleep on energy expenditure, core body temperature, and appetite: a human randomised crossover trial.

The effects of sleep restriction on energy metabolism and appetite remain controversial. We examined the effects of shortened sleep duration on energy metabolism, core body temperature (CBT), and appetite profiles. Nine healthy men were evaluated in a randomised crossover study under two conditions: a 3.5-h sleep duration and a 7-h sleep duration for three consecutive nights followed by one 7-h recovery sleep night. The subjects’ energy expenditure (EE), substrate utilisation, and CBT were continually measured for 48 h using a whole-room calorimeter. The subjects completed an appetite questionnaire every hour while in the calorimeter. Sleep restriction did not affect total EE or substrate utilisation. The 48-h mean CBT decreased significantly during the 3.5-h sleep condition compared with the 7-h sleep condition (7-h sleep, 36.75 ± 0.11 °C; 3.5-h sleep, 36.68 ± 0.14 °C; p = 0.016). After three consecutive nights of sleep restriction, fasting peptide YY levels and fullness were significantly decreased (p = 0.011), whereas hunger and prospective food consumption were significantly increased, compared to those under the 7-h sleep condition. Shortened sleep increased appetite by decreasing gastric hormone levels, but did not affect EE, suggesting that greater caloric intake during a shortened sleep cycle increases the risk of weight gain.

Practical human abdominal fat imaging utilizing electrical impedance tomography.

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 subjects 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.

Imaging and estimation of human abdominal fat by electrical impedance tomography using multiple voltage measurement patterns

A measuring device for human abdominal fat from the conductivity image derived by electrical impedance tomography (EIT) is rarely found. This study was aimed to reconstruct precise conductivity images from multiple voltage measurements in different patterns of the combination of current and voltage electrodes. We examined two voltage measuring patterns using electrodes located at upper and lower levels around the abdomen of a subject. In the experiment, after 1024 voltage data were taken from one specified voltage measurement pattern, another 1024 data were also taken continuously using another pattern. The reconstruction of conductivity image was made using entire data. As a result, the tomography image was improved compared with the image obtained from single voltage measurement pattern. We then obtained the histogram of the conductivities and estimated the area of abdominal fat. The present method using multiple voltage measurement patterns would be effective, if the measuring time can be much reduced through future modification of the tomography device.

Effects of Visceral Fat Accumulation Awareness on a Web-Based Weight-Loss Program: Japanese Study of Visceral Adiposity and Lifestyle Information—Utilization and Evaluation (J-VALUE)

A reduction of visceral fat is important for improvement of metabolic risk. This study was designed to compare the effects of a web-based program alone or together with measurement and self-awareness of accumulated visceral fat in Japanese workers. A new noninvasive device to measure visceral fat accumulation was introduced, and efficacy on weight-loss and improvement of healthy behaviors were examined. This study was conducted according to Helsinki declaration and approved by the ethical committee of Japan Hospital Organization, National Kyoto Hospital. Two-hundred and sixteen overweight and obese males with BMI of more than 23 participated from 8 healthcare offices of 3 Japanese private companies. Subjects were randomly allocated into control group, Web-based weight-loss program (Web), or Web + Visceral fat measurement group (Web + VFA). Eighty-one percent of participants completed the study. Reductions of body weight, waist circumference, and BMI were the largest in Web + VFA group, and the differences between groups were significant by ANOVA. Improvements of healthy behaviors were the largest in Web + VFA group, and the differences of healthy eating improvement scores between Web + VFA and control groups were significant. Our findings suggest that measurement and awareness of visceral fat are effective in weight reduction in overweight and obese males in the workplace.

Actual Daily Intakes of Tea Catechins and Thier Estimation According to Four Season 3 Day Weighed Dietary Records and a Short Food Frequency Questionnaire among Japanese Men and Women

Background: Tea catechins are considered to be important preventive factors of cancer on several organs; however, the relationships of the actual daily intakes (ADIs) on the preventive effects have not been adequately addressed. We measured the ADIs of tea catechins as annual averages derived from every their ingested cups recorded by each subject, and the estimation models were established considering tea origin. Methods: Fifty-nine Japanese men and women completed four season 3 day weighed dietary records (WDRs) and a food frequency questionnaire (FFQ), and samples of green, oolong and black teas, ingested during a total 12 days were collected for the analysis. The ADIs of the total and composed catechins of all tea samples were measured by a high-performance liquid chromatography. The estimation models for the ADIs (R2: coefficient of determination) based on the WDRs and FFQ were established with multiple regression analysis using appropriate confounding factors. V Results: The ADIs of total catechins and epigallocatechin gallate (EGCg) were 110 and 21.4 mg/day in men and 157 and 34.7 mg/day in women, respectively. The total catechins ADIs were positively associated with green tea consumption based on WDRs and FFQ (adjusted R2 =0.421 and 0.341 for men and 0.346 and 0.238 for women, p<0.05 for all, respectively). Likewise, the EGCg ADIs were associated with green tea intake derived from WDRs and FFQ, respectively. Conclusions: We revealed the ADIs of total catechins and EGCg as annual averages could establish their estimation models. These provide reference information to clarify their relationships with cancer risks.