Number 62 (December 5, 2019)

Health andNutrition News

No.62

Contents

Motohiko Miyachi
Department of Physical Activity Research

How much energy are athletes expending? ･･････････････････････ 3
Kazuko Ishikawa-Takata
Section of Dietary Guideline, Department of Nutrition and Metabolism

External Quality Assessment Surveys of Food Nutrition Analysis
in Japan ･････････････････････････････････････････････････････ 4
Jun Takebayashi
Section of Food Component Analysis, Department of Food Function and Labeling

Nayu Ikeda
Section of Population Health Metrics, International Center for Nutrition and Informationo.6 2

Global trends in the urban-rural difference inadult body mass index ･････････････････････････････････････････ 5

Health and Nutrition News N

Effects of 1-year weight loss intervention on abdominal skeletal
muscle mass in Japanese overweight men and women ･････････････ 2Role of Brain Insulin Receptor Substrate-1Role of Brain Insulin
Receptor Substrate-1 (Irs1) in Growth and Glucose
Metabolism(Irs1) in Growth and Glucose Metabolism ････････････ 6
Takanori Hayashi
Section of Nutrition Therapy, Department of Clinical Nutrition

Association between the Portion Sizes of Traditional Japanese
Seasonings—Soy Sauce and Miso—and Blood Pressure: the 2012–2016 Japan National Health and Nutrition Survey ･････････････････ 7
Emiko Okada
Section of the National Health and Nutrition Survey, Department of Nutritional
Epidemiology and Shokuiku

Welcome to the official website of our institute ･･････････････････ 8
Section of Research Collaboration and Partnership

National Institutes of Biomedical Innovation, Health and Nutrition

National Institute of Health and Nutrition1

Effects of 1-year weight loss intervention on
abdominal skeletal muscle mass in Japanese
overweight men and women
Motohiko Miyachi, Department of Physical Activity Research

Before and after the one-year lifestyle intervention for【Introduction】
Quantitative assessment of visceral fat mass andskeletal muscle mass is important from the viewpointof lifestyle-related disease prevention. Recently, it has
been suggested

that

fat

cells

and

musclecells

interact in a reciprocal manner. In addition, the decreasein abdominal skeletal muscle due to aging is larger

weight loss, an abdominal transverse image was acquired
using computed tomography. The cross-sectional areas(CSAs) of visceral fat, subcutaneous fat, and skeletal
muscle of the rectus abdominis, abdominal oblique,iliopsoas, and erector spinae muscle were calculated.

than that in extremity skeletal muscle, and it may【Results】

be adversely affected by visceral fat accumulation.

The body weight changed by approximately -5% in the【Purpose】

intervention group. The corresponding values for

The purpose of this study was to examine 1) the
relationshipbetweenvisceral

fat

mass

and

abdominal skeletal muscle mass in obese subjects and 2)
the effects of weight loss programs on abdominal fat
mass and skeletal muscle mass.

【Method】
A total of 235 overweight Japanese men and women
aged 40–64 years with a body mass index of 28.0 to 44.8
kg/m2 participated in this randomized controlledintervention study. They were randomly divided into alifestyle intervention group and control group.

subcutaneous fat and visceral fat CSAs were -10.8 to-17.5% in both sexes. The reductions observed in skeletal
muscle CSAs were significantly less (-6.0% and -7.2% in
the male and female intervention groups, respectively) thanthose in fat tissue CSAs. The CSA of each of the fourskeletal muscle groups also significantly decreased;
however, after adjustments for body weight at each time
point, only reductions in the iliopsoas muscle in both sexes
and abdominal oblique muscles in men remained
significant.

【Conclusion】
The lifestyle weight loss intervention might reduce therelative amount of abdominal skeletal muscles especiallyiliopsoas muscles.

【Future direction】
It was suggested that measures to prevent a decrease in
the abdominal skeletal muscle mass should be examined
during weight loss intervention in obese individuals.
This report is part of the result of the Saku Obesity Control
Program (SCOP), and details are published in the following
two papers.

Figure 1. The CSAs of subcutaneous fat
and abdominal skeletal muscles, i.e., the rectus a
bdominis 1, abdominal oblique 2, iliopsoas muscl
es 3, and erector spinae 4, were semi-automatica
ll y c a l c u l a t e d b y a w e l l - t r a i n e d m e a s u r e r u s i n g C
T images.

2

Health and Nutrition News No. 62

Tanaka et.al. Asia Pac J Clin Nutr. 2019; 28 (1): 72-78.
Tanaka et.al. Obes Res Clin Pract. 2018; 12 (4): 378-383.

How much energy are athletes expending?
Kazuko Ishikawa-Takata
Section of Dietary Guideline, Department of Nutrition and Metabolism

We studied energy expenditure using the doubly labeled

Highly trained athletes can maintain the energy balancewater (DLW) method. Athletes will expend great amounts

between energy expenditure and intake as much as aof energy compared with that expended by sedentary

PAL of 5.00. However,subjects because of participation in vigorous training.

athletes

Physical activities during training vary; thus, it is difficult

intake. It may be difficult to maintain energy balance

to assess energy expenditure using simple methods,

only by consuming natural foods.

such

as

using

an

accelerometer

or

based

on

questionnaires. The DLW method is an adequate method
to assess physical activity levels among athletes.

case,

most

consume supplements to increase energy【Future research】
Compared with measuring energy expenditure using DLW
energy intake corresponding with energy expenditure.

The subjects were bodybuilders and college students who
were long- or intermediate-distance runners, swimmers,
rhythmic gymnasts, lacrosse players, track and field
sprinters, or Korean college tennis players. The athletes
drank water including stable isotopes of hydrogen andoxygen, and urine samples were collected once a day for
one week. We analyzed the stable isotope concentrationin the urine samples.

【Results and discussion】
Our published results are summarized in the table (1–5).
The maximum physical activity level (PAL= total energy
expenditure/resting metabolic rate) was shown in longdistance runners (2.68) and minimum PAL was shown in
Korean tennis players (1.97). Per the Dietary Reference
Intake Japan 2015, the PAL for a moderately active adultis 1.75 and that for an active adult is 2.00. Most of thehighly trained athletes showed equal or higher PALs thanthose in active adults. Westerterp KR suggested that asustainable limit of the PAL for the general population is
2.5.

Body builder (men)Long or middle distance runner (women)
Swimmer (women)
Rhythmic gymnastics (women)
lacrosse players (women)
Track and field sprinter (women)
Tennis player (women)Long distance runner (women)that

methods, it is quite difficult to assess the adequacy of【Subjects and method】

Sportsin

Estimating energy balance from the changes in bodycomposition or body mass is also inappropriate because
athletes are training to achieve desirable bodies. The
assessment of energy balance is a problem to be solved.

【References】
1) Yamamoto S et al. Basal metabolic rate and physical activity
level in bodybuilders, The Japanese Journal of Nutrition andDietetics, 66, 195-200, 2008
2) Yosida A et al., Factors associated with reporting error forenergy intake estimated by food record in female athletes, The
Japanese Journal of Nutrition and Dietetics, 77, 305-315, 2012
3) Yoshida A et al., Self-consciousness in female sprinter isassociated with reporting error for energy intake estimatedfrom food records, J Jpn Soc Nutr Food Sci, 66, 101-107, 2013
4) Didace Ndahimana et al., Accuracy of dietary reference
intake predictive equation for estimated energy requirements
in female tennis athletes and non-athlete college students:
comparison with the doubly labeled water method, Nutr Res
Prac, 11, 51-56,2017
5) Yoshida A et al., Validity of combination use of activity
record and accelerometry to measure free-living total energy
expenditure in female endurance runners, J Strength
Condition Res, in press6) Westerterp KR. Limits to sustainable human metabolic rate.
J. Exp. Biol 204,3183,2001

N

Total Energy
expenditure(kcal/day)

Resting
Physical activity
metabolic ratelevel
(kcal/day)

Ref.

7
9
10
7
12
12
8
8

3,432±663
2,673±620
3,077±346
2,910±224
2,910±277
2,392±376
2,780±430
3,032±344

1,687±178
1,200±222
1,300±209
1,121±150
1,220±168
1,069±144
1,407±170
―

1）
2）
2）
2）
2）
3）
4）
5）

2.03±0.23
2.23±0.33
2.45±0.41
2.65±0.47
2.44±0.47
2.3±0.30
1.97±0.17
2.68±0.37

Health and Nutrition News No. 623External Quality Assessment Surveys of Food
Nutrition Analysis in Japan
Jun Takebayashi, Section of Food Component Analysis, Department of Food Function and Labeling【Introduction】
In Japan, under the Food Labeling Law enforced in 2015,
all processed foods will be essentially labeled with thecontents of nutrients from April 2020: namely, energy,
protein, fat, carbohydrate, and salt equivalent values.
Nutrient labeling is essential information that shows theamounts of invisible nutrients and helps consumers selectsuitable products. There are two types of nutrition
declarations (Figure 1). One case is that in whichcalculated values from the Japanese food standard
composition table or analytical values of a sample productare displayed. In these cases, note that "estimated value"or "this value is a rough indication" should accompany
these values, indicating that the declared values might notalways match the actual nutrient contents. The other caseis that in which no such notices are displayed; the amountsof nutrients contained in each product are qualitycontrolled within the range of -20% to +20% of thedeclared values.*
Laboratory analysis is necessary to determine the correct
amounts of nutrients. However, laboratory analytical values
should include considerable errors. Therefore, wedeveloped a method to assess the reliability of analyticallaboratories for information regarding food nutrients.1),2)
We have provided external quality assessment surveys offood nutrition analysis in cooperation with the Food andDrug Safety Center since 2017.

【Subjects and Methods】
The
surveywasconducted
amongpublicanalytical laboratories. In both 2017 and 2018,
54 participants were distributed sausages that were
specially preparedfor
thissurvey.
Eachlaboratory independently determined the amounts ofnutritional components, and we compared thereportedvalues among
thelaboratories.
The
criteria
forgood laboratory
performancewere
as follows: i) the reported value is within thestatistically acceptable range (-3 < z-score < 3)
and ii) the reported value is within ±20% of theaverage value.

Figure 1. Two ways of nutrition declaration

4

Health and Nutrition News No. 62【Results】

About 10% of the participants both in 2017 and 2018
reported
unsuitablevaluesforoneormore mandatory nutrients (Table 1). In particular,
the reported values for carbohydrateor
salt
equivalent values tended to be inappropriate.

【Future direction】

As of 2019, we are conducting an external
quality control survey using a cereal product as the test
food. The accuracy of laboratory analysis can be
improved by repeatedly participating in external quality
control surveys. We will continue researching the reliabilityof food nutrition declarations.

Note* Each nutrient has specific tolerance ranges: energy,
protein, fat, carbohydrate, and salt equivalent = -20% to+20%; minerals and fat-soluble vitamins = -20% to+50%; and water-soluble vitamins = -20% to +80%.

【References】
1) Jun Takebayashi, Teruki Matsumoto, Yoshiko Ishimi.
Ensuring the Reliability of Nutrition Labeling Values: A Preliminary
Study on the Establishment of a Methodology for Proficiency
Testing of Laboratories for Nutritional Analysis. The Japanese
Journal of Nutrition and Dietetics. 73, 8-15 (2015).
2) Jun Takebayashi, Teruki Matsumoto, Yoshiko Ishimi.
Ensuring the Reliability of Nutrition Labeling Values: An Attempt
at Proficiency Testing of Major Nutrients Analysis. The
Japanese Journal of Nutrition and Dietetics. 75, 3-18 (2017).

Table 1. Number of the laboratories which
reported suitable or unsuitable values inexternal quality assessment surveys in2017 and 2018

Global trends in the urban-rural difference inadult body mass index
Nayu Ikeda, Section of Population Health Metrics, International Center for Nutrition and Information

Mean body mass index (BMI) has increased gradually inmost countries in parallel with a rise in the proportion of
the urban population. This has led to a widely reported
view that urbanization is one of the most important driversof the global rise in the prevalence of overweight andobesity. However, a study of global trends in BMI by the
Non-Communicable
Disease
Risk
FactorCollaboration (NCD-RisC) reported that excessive
weight is increasing more rapidly in the world’s rural
areas than in urban areas.
The NCD-RisC is a worldwide network of healthresearchers and practitioners for studying the global
trends and variations in risk factors for noncommunicable diseases. I have collaborated with
the NCD-RisC as part of my research funded by theJapan Society for the Promotion of Science for the past
several years. I had an opportunity to contribute as amember of the Writing Group for a paper published in
Nature.
We analyzed the height and weight data of more than
112 million adults to estimate trends in mean BMI from1985 to 2017 by rural and urban place of residence for200
countries
andterritories.
The
data
included information provided from a number of national
and local surveys in Japan, such as the National
Health and Nutrition Survey.
The study found that from 1985 to 2017, BMI rose by
an average of 2.0 kg/m2 in women and 2.2 kg/m2 in men
globally. More than half of the global rise over these 33
years was attributable to increases in rural BMI. In somelow- and middle-income countries, rural areas were
accountable for over 80% of the increase.

Moreover, since 1985, mean BMI in rural areas has
increased by 2.1 kg/m2 in both women and men, while incities, the increase was 1.3 kg/m2 and 1.6 kg/m2 inwomen and men, respectively.
These trends have led to noticeable changes in thegeography of BMI over the past three decades. In 1985,
urban men and women had a higher BMI than theirrural counterparts in over three quarters of the countries.
Over time, the difference between urban and rural
BMI decreased or even reversed in many of thesecountries (Figure).
Policy implications
As economic growth and rural nutrition programs solve a
caloric deficit in rural areas, the rural undernutrition
disadvantage may be replaced by a more generaland complex malnutrition that entails excessive
consumption of low-quality calories. To avoid suchan unhealthy transition, the fragmented national
and international responses to undernutrition andobesity should be integrated, and the narrow focus ofinternational aid on undernutrition should be broadened
to enhance access to healthier foods in poor rural andurban communities.
Acknowledgement
This study was funded in part by the Japan Society for
the Promotion of Science (PI: Nayu Ikeda, grant numbers
15K08762 and 18H03063).

【Reference】
NCD Risk Factor Collaboration (NCD-RisC). Rising rural bodymass index is the main deriver of the global obesity epidemic inadults. Nature 2019:569;260-264.
https://www.nature.com/articles/s41586-019-1171-x

Edited from Nature 2019:569;260-264.

© 2019 NCD Risk Factor Collaboration

Figure. The difference between rural and urban age-standardized mean BMI

Health and Nutrition News No. 62

5Role of Brain Insulin Receptor Substrate-1(Irs1) in Growth and Glucose Metabolism
Takanori Hayashi, Section of Nutrition Therapy, Department of Clinical Nutrition

6【Introduction】【Subjects and Methods】

In the recent years, the prevalence of type 2
diabetes has been considerably increasing
worldwide. Hence, it is crucial and imperative todevelop strategies for preventing the disease onset
and minimize complications. Insulin receptor
substrates (Irs) are activated by insulin and insulinlike growth factor (IGF)-1 receptors and allow
docking of downstream effectors. Hence, they are
essential for insulin and IGF signaling. In particular,
Irs1 and Irs2 play a key role in glucose
homeostasis. Our previous study demonstrated thatIrs1 plays an important role in not only glucose
homeostasis but also growth in whole-body Irs1knockout mice. However, the underlying molecularmechanisms and tissues or organs responsible forIrs1-mediated growth are unclear.
Since recent evidence has revealed that insulin
action in the brain contributes to the regulation offood intake and hepatic glucose production, it is
now apparent that the brain, in addition to the liver,adipose tissues, and skeletal muscles, is an
insulin-sensitive organ. However, the role of Irs1 inthe brain remains unknown. Hence, the present
study aimed to investigate the role of Irs1 in thebrain.

We generated brain-specific Irs1 knockout(NIrs1KO) mice and analyzed growth relatedparameters and metabolic factors.

Health and Nutrition News No. 62【Results】
NIrs1KO mice showed decreased body weightand shorter body and bone length compared tocontrol mice.
Hypothalamic
GHRH
mRNA
expression
levels in NIrs1KO mice weresignificantly lower than those in the control
mice.
Moreover,NIrs1KOmice showed
increased insulin sensitivity and enhanced
glucose utilization.

【Future Direction】
This study demonstrated that Irs1 in thebrain regulates
bothsomatic
growthandglucose metabolism. Further research on thesemolecular mechanisms is necessary for theprevention and treatment of diabetes.

【References】
１）Tamemoto H et al. Insulin resistance and growth retardation in mice lacking insulin receptor substrate-1. Nature.
372（6502）:182-6. 1994
２）Inoue H et al. Role of hepatic STAT3 in brain-insulin action on hepatic glucose production. Cell Metab. 3（4）: 26775. 2006

Association between the Portion Sizes of Traditional Japanese
Seasonings—Soy Sauce and Miso—and Blood Pressure: the 2012–2016 Japan National Health and Nutrition Survey
Emiko Okada, Section of the National Health and Nutrition Survey,
Department of Nutritional Epidemiology and Shokuiku【Introduction】

Hypertension is an important global public healthchallenge. Risk factors for hypertension are known to
be overweight, obesity, high salt intake, insufficient intakeof fruits and vegetables, high alcohol consumption,and physical inactivity. Some previous studies has
been shown that high salt intake was associated withhigher blood pressure and higher risk of cardiovasculardisease among Japanese population. In Japanese,seasoning are major
sourcessaltintake.
Inparticular,
traditional Japanese
seasonings--soysauce and miso--have a high sodium content. It is
important to consider food portion sizes (the amountof food consumed per dish) when assessing the healtheffects of food. Therefore, this study aimed toinvestigate the association between the portion sizes ofsoy sauce and miso and blood pressure.

【Methods】

Study participants were 25,738 Japanese aged ≥20 years
registered in the 2012–2016 National Health and Nutrition
Survey who had blood pressure measurements and notusing blood pressure-lowering drugs. Portion sizes of soy
sauce and miso were calculated the total weight of the soy
sauce or miso consumed in all the meals of the day
divided by the number of dishes that used soy sauce or
miso. Hypertension was defined as SBP ≥140 mmHg and/or DBP ≥90 mmHg. Data analysis was used multiple
logistic regression analysis for association between the
portion sizes of soy sauce and miso and blood pressure.

【Results】
A total of 7,279 of the participants had hypertension.
The median portion size values were 4.0 g for men and 3.5
g for women (soy sauce), and 9.0 g for men and 8.67 g for
women (miso). Participants with a larger portion size of soy
sauce or miso were older and had a higher intake of almost
all foods and nutrients, but a lower intake of meat, milk,fats and oils, confectioneries, and fat. No significant
association between the portion sizes of soy sauce or miso
and hypertension were observed in the multivariate model
after adjusted confounding factors in both sexes (figure).

【Future direction】
Our findings suggest that the portion sizes of soy sauceor miso are not associated with hypertension
among Japanese adults. Participants with a larger portion
size of soy sauce or miso had a diet with higher
intake of vegetables,
fruits,andfisheswhich
containhigher potassium, is consider a factor. In
addition to seasonings, salt is also taken fromprocessed foods such as cup noodle, so various
analyzes are required. Because low-salt soy sauce miso
have become widespread in recent years, we plan toevaluate and examine these usage conditions.

【Reference】
Okada E, et al. Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012-2016 Data. Nutrients. 10（12）.pii: E1865. 2018.

Health and Nutrition News No. 62

7

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Health and Nutrition News No. 62