日: 2014年9月18日

Protein

RecommendeAmountProtein

The reports of protein have 9 pages and 73 references in 2010 edition and 14 pages and 119 references in 2015 edition, respectively.

Although upper limit of protein intake is not set in 2010 edition, it’s preferred that protein intake is less than 2.0 g/kg/d in adult.

It is focused on severity of disease in 2015 edition. If protein-energy ratio was greater than 20 % energy, the risk of diabetes, cardiovascular disease, the incidence of cancer, bone loss and the increase of BMI would develop. Then it should be noted that protein-energy ratio should not be more than 20 % energy.

Estimated Average Requirement of indispensable amino acids (essential amino acids) has been described for only adult in 2010 edition and they have been described not only for adult but also for child and infant in 2015 edition, respectively.

Dietary reference intakes of the proteins of the 2015 edition is as follow table.

Dietary Reference Intakes of the proteins (g/d), Target (median) % energy) 2015 edition
Gender Male Female
Age Estimated Average Requirement Recommended amount Approximate amount Target amount (Median) Estimated Average Requirement Recommended amount Approximate amount Target amount (Median)
0-5 M 10 10
6-8 M 15 15
9-11 M 25 25
1-2 15 20 13-20 (16.5) 15 20 13-20 (16.5)
3-5 20 25 13-20 (16.5) 20 25 13-20 (16.5)
6-7 25 35 13-20 (16.5) 25 30 13-20 (16.5)
8-9 35 40 13-20 (16.5) 30 40 13-20 (16.5)
10-11 40 50 13-20 (16.5) 40 50 13-20 (16.5)
12-14 50 60 13-20 (16.5) 45 55 13-20 (16.5)
15-17 50 65 13-20 (16.5) 45 55 13-20 (16.5)
18-29 50 60 13-20 (16.5) 40 50 13-20 (16.5)
30-49 50 60 13-20 (16.5) 40 50 13-20 (16.5)
50-69 50 60 13-20 (16.5) 40 50 13-20 (16.5)
70- 50 60 13-20 (16.5) 40 50 13-20 (16.5)
Additional protein in early pregnant 0 0
Additional protein in mid pregnant 5 10
Additional protein in late pregnant 20 25
Additional protein in lactation 15 20

Dietary reference intakes of the proteins of the 2010 edition is as follow table.

Dietary Reference Intakes of the proteins (g/d) 2010 edition
Gender Male Female
Age Estimated Average Requirement Recommended amount Approximate amount Upper limit amount Estimated Average Requirement Recommended amount Approximate amount Upper limit amount
0-5 M 10 10
6-8 M 15 15
9-11 M 25 25
1-2 15 20 15 20
3-5 20 25 20 25
6-7 25 30 25 30
8-9 30 40 30 40
10-11 40 45 35 45
12-14 45 60 45 55
15-17 50 60 45 55
18-29 50 60 40 50
30-49 50 60 40 50
50-69 50 60 40 50
70- 50 60 40 50
Additional protein in early pregnant 0 0
Additional protein in mid pregnant 5 10
Additional protein in late pregnant 20 25
Additional protein in lactation 15 20

The recommended amount is based on the proteins maintain the required amount from nitrogen balance experiment, corrected in the digestibility of daily meal mixed protein, used to calculate the reference value of the Estimated Average Requirement calculation and is calculated the recommended amount by the addition of interindividual variability.

Recommended amount of protein (g/d) is product of Estimated Average Requirement and Recommended amount calculated coefficient. The Estimated Average Requirement is product of Reference value of the Estimated Average Requirement Calculation (g/kg/d) and reference weight (kg). Reference value of the Estimated Average Requirement calculation is obtained by dividing protein maintain the required amount (g/kg/d) by the digestibility.

Recommended amount calculated coefficient is 1.25. The digestibility is 0.9.

Adult

The proteins maintain the required amount of adult, that has been determined from the average of 17 studies examined the nitrogen balance maintenance dose of animal protein, is 0.65 g/kg/d, divided it by the digestibility 0.9, Reference value of the Estimated Average Requirement Calculation is obtained as 0.72 g/kg/d.

\mathrm{Estimated\ Averege\ Requirement}=0.72\times\mathrm{Reference\ Weight}
\mathrm{Recommended\ Amount}=\mathrm{Estimated\ Average\ Requirement}\times1.25

Elderly

Estimated Average Requirement of protein of elderly, that have been calculated from the pooled analysis using 144 data nitrogen balance of 60 subjects of five studies, is 0.85 g/kg/d (corrected by the digestibility).

Child

The reference value for calculation of Estimated Average Requirement in child the sum of the required amount of protein maintenance and the amount of protein accumulation. The Estimated Average Requirement is the product of the reference value for calculation of Estimated Average Requirement and reference weight. The recommended amount is the product of the Estimated Average Requirement and recommended amount calculation coefficient 1.25. The required amount of protein maintain is 0.67 g/kg/d.

Estimated Average Requirement and recommended amount of protein about child is following table. Predictive equation following is correct in 2015 edition, although predictive equation of 2010 edition is wrong.

Estimated Average Requirement and recommended amount of protein about child 2015 edition
Male child
A B C D E F G H I
Age (Y) Reference weight (kg) Weight gain (kg/Y) Body protein (%) Body protein accumulation (g/kg/d) Accumulation efficiency (%) Proteins maintain the required amount (g/kg/d) Utilization efficiency (%) Estimated Average Requirement (g/d) Recommended amount (g/d)
1-2 11.5 2.1 13.2 0.064 40 0.67 70 12.9 16.1
3-5 16.5 2.1 14.7 0.050 40 0.67 70 17.9 22.3
6-7 22.2 2.7 15.5 0.051 40 0.67 70 24.1 30.1
8-9 28.0 3.2 14.5 0.046 40 0.67 70 30.0 37.5
10-11 35.6 4.7 13.9 0.050 40 0.67 75 36.3 45.3
12-14 49.0 5.1 13.9 0.039 40 0.67 80 45.9 57.3
15-17 59.7 2.0 15.0 0.014 40 0.67 85 49.1 61.4
Female child
A B C D E F G H I
Age (Y) Reference weight (kg) Weight gain (kg/Y) Body protein (%) Body protein accumulation (g/kg/d) Accumulation efficiency (%) Proteins maintain the required amount (g/kg/d) Utilization efficiency (%) Estimated Average Requirement (g/d) Recommended amount (g/d)
1-2 11.0 2.2 13.0 0.070 40 0.67 70 12.5 15.6
3-5 16.1 2.1 14.1 0.051 40 0.67 70 17.5 21.8
6-7 21.9 2.5 14.1 0.045 40 0.67 70 23.4 29.3
8-9 27.4 3.4 13.7 0.046 40 0.67 70 29.4 36.7
10-11 36.3 5.1 14.6 0.057 40 0.67 75 37.6 47.0
12-14 47.5 3.0 14.8 0.026 40 0.67 80 42.8 53.6
15-17 51.9 0.7 11.9 0.004 40 0.67 85 41.5 51.8
\displaystyle D = \frac{B\times1,000}{365} \times \frac{C}{100 \times A}\\ \\ H = \left( \frac{D}{E} \times 100 + \frac{F}{G} \times 100 \right) \times A\\ \\ I = H \times 1.25

Infant

The target amount of protein in infant in human milk is 9.83 g/d in 0-5 months, 12.5 g/d in 6-8 months and 22.0 g/d in 9-11 months, respectively. The target amount in artificial feeding is 14.0 g/d in 0-5 months, 15.2 g/d in 6-8 months and 23.8 g/d in 9-11 months, respectively.

Pregnant

It’s assumed that the weight gain in full-term is 11.0 kg in pregnant. The additional protein is obtained indirectly by calculating the body potassium increased amount. Estimated Average Requirement is 0 g/d in early pregnant, 4.51 g/d in mid pregnant and 18.98 g/d in late pregnant, respectively. The recommended amount of additional protein is 0 g/d in early pregnant, 5.64 g/d in mid pregnant and 23.73 g/d in late pregnant, respectively.

Lactation

Estimated Average Requirement of lactation is 14.04 g/d and recommended amount is 17.6 g/d, respectively. The average milk yield per day is 0.78 L/d and the average of the protein concentration in human milk is 12.6 g/L, respectively. Conversion efficiency of human milk protein from dietary protein is 70 %.

Reference:
Protein (The Dietary Reference Intakes for Japanese 2015 edition) (pdf)
Protein (The Dietary Reference Intakes for Japanese 2010 edition) (pdf)

たんぱく質

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　たんぱく質についての記載は 2010 年版では 9 ページ，参考文献は 73 件ですが 2015 年版では 14 ページ，参考文献 119 件に増えています．

　2010 年版では耐用上限量を設定していませんが，成人においてはたんぱく質摂取量は 2.0 g/kg/d 未満に留めるのが望ましいとしています．

　2015 年版では生活習慣病の重症化予防に重点を置いており，たんぱく質エネルギー比率が 20 % エネルギーを超えた場合の健康障害として糖尿病発症リスクの増加，心血管疾患の増加，がんの発症率の増加，骨量の減少，BMI の増加を挙げて，たんぱく質エネルギー比率が 20 % エネルギーを超えないように注意を喚起しています．

　不可欠アミノ酸（必須アミノ酸）の推定平均必要量については 2010 年版では成人のみ記載されていましたが 2015 年版では乳児・小児についても記載が追加されています．

　2015 年版のたんぱく質の食事摂取基準は下表のとおりです．

たんぱく質の食事摂取基準（推定平均必要量・推奨量・目安量 (g/d), 目標量（中央値） % エネルギー）2015 年版
性別 男性 女性
年齢 推定平均必要量 推奨量 目安量 目標量 (中央値) 推定平均必要量 推奨量 目安量 目標量 (中央値)
0-5 M 10 10
6-8 M 15 15
9-11 M 25 25
1-2 15 20 13-20 (16.5) 15 20 13-20 (16.5)
3-5 20 25 13-20 (16.5) 20 25 13-20 (16.5)
6-7 25 35 13-20 (16.5) 25 30 13-20 (16.5)
8-9 35 40 13-20 (16.5) 30 40 13-20 (16.5)
10-11 40 50 13-20 (16.5) 40 50 13-20 (16.5)
12-14 50 60 13-20 (16.5) 45 55 13-20 (16.5)
15-17 50 65 13-20 (16.5) 45 55 13-20 (16.5)
18-29 50 60 13-20 (16.5) 40 50 13-20 (16.5)
30-49 50 60 13-20 (16.5) 40 50 13-20 (16.5)
50-69 50 60 13-20 (16.5) 40 50 13-20 (16.5)
70- 50 60 13-20 (16.5) 40 50 13-20 (16.5)
妊婦初期付加量 0 0
妊婦中期付加量 5 10
妊婦後期付加量 20 25
授乳婦 付加量 15 20

　2010 年版のたんぱく質の食事摂取基準は下表のとおりです．

たんぱく質の食事摂取基準 (g/d) 2010 年版
性別 男性 女性
年齢 推定平均必要量 推奨量 目安量 耐用上限量 推定平均必要量 推奨量 目安量 耐用上限量
0-5 M 10 10
6-8 M 15 15
9-11 M 25 25
1-2 15 20 15 20
3-5 20 25 20 25
6-7 25 30 25 30
8-9 30 40 30 40
10-11 40 45 35 45
12-14 45 60 45 55
15-17 50 60 45 55
18-29 50 60 40 50
30-49 50 60 40 50
50-69 50 60 40 50
70- 50 60 40 50
妊婦初期付加量 0 0
妊婦中期付加量 5 10
妊婦後期付加量 20 25
授乳婦 付加量 15 20

　窒素出納実験により測定された動物性たんぱく質のたんぱく質維持必要量をもとに，それを日常食混合たんぱく質の消化率で補正して推定平均必要量算定の参照値を算定し，その上に個人間変動を加えて推奨量を算定します．

　たんぱく質の推奨量 (g/d) は，推定平均必要量 (g/d) と推奨量算定係数との積です．推定平均必要量は，推定平均必要量算定の参照値 (g/kg/d) と参照体重 (kg) との積です．推定平均必要量算定の参照値は，たんぱく質維持必要量 (g/kg/d) を消化率で除した値です．

　推奨量算定系数は 1.25 です．消化率は 0.9 です．

成人

　動物性たんぱく質の窒素出納維持量を検討した 17 の研究の平均値から求めた成人のたんぱく質維持必要量は 0.65 g/kg/d で，消化率 0.9 で割ると推定平均必要量算定の参照値は 0.72 g/kg/d です．

\mathrm{Estimated\ Averege\ Requirement}=0.72\times\mathrm{Reference\ Weight}
\mathrm{Recommended\ Amount}=\mathrm{Estimated\ Average\ Requirement}\times1.25

高齢者

　高齢者のたんぱく質推定平均必要量は 0.85 g/kg/d です（ただし消化率で補正済み）．5 つの研究の 60 名の被験者の窒素出納 144 データを用いたプール解析から算出した値です．

小児

　小児の推定平均必要量算定の参照値は，たんぱく質維持必要量とたんぱく質蓄積量の和です．推定平均必要量は，推定平均必要量算定の参照値に参照体重を乗じて求めます．推奨値は推定平均必要量に推奨量算定係数 1.25 を乗じた値です．たんぱく質維持必要量は 0.67 g/kg/d です．

小児についてはさらに下表のように詳細な記載があります．2010 年版もありますが，基準体重の数値およびその計算結果が異なるだけなので掲載しません．また小児の推定平均必要量算定の参照値を求める下式は 2010 年版は誤りで，2015 年版が正しい式です．

小児の推定平均必要量，推奨量 2015 年版
男子
A B C D E F G H I
年齢 (Y) 参照体重 (kg) 体重増加量 (kg/Y) 体たんぱく質 (%) 体たんぱく質蓄積量 (g/kg/d) 蓄積効率 (%) たんぱく質維持必要量 (g/kg/d) 利用効率 (%) 推定平均必要量 (g/d) 推奨量 (g/d)
1-2 11.5 2.1 13.2 0.064 40 0.67 70 12.9 16.1
3-5 16.5 2.1 14.7 0.050 40 0.67 70 17.9 22.3
6-7 22.2 2.7 15.5 0.051 40 0.67 70 24.1 30.1
8-9 28.0 3.2 14.5 0.046 40 0.67 70 30.0 37.5
10-11 35.6 4.7 13.9 0.050 40 0.67 75 36.3 45.3
12-14 49.0 5.1 13.9 0.039 40 0.67 80 45.9 57.3
15-17 59.7 2.0 15.0 0.014 40 0.67 85 49.1 61.4
女子
A B C D E F G H I
年齢 (Y) 参照体重 (kg) 体重増加量 (kg/Y) 体たんぱく質 (%) 体たんぱく質蓄積量 (g/kg/d) 蓄積効率 (%) たんぱく質維持必要量 (g/kg/d) 利用効率 (%) 推定平均必要量 (g/d) 推奨量 (g/d)
1-2 11.0 2.2 13.0 0.070 40 0.67 70 12.5 15.6
3-5 16.1 2.1 14.1 0.051 40 0.67 70 17.5 21.8
6-7 21.9 2.5 14.1 0.045 40 0.67 70 23.4 29.3
8-9 27.4 3.4 13.7 0.046 40 0.67 70 29.4 36.7
10-11 36.3 5.1 14.6 0.057 40 0.67 75 37.6 47.0
12-14 47.5 3.0 14.8 0.026 40 0.67 80 42.8 53.6
15-17 51.9 0.7 11.9 0.004 40 0.67 85 41.5 51.8
\displaystyle D = \frac{B\times1,000}{365} \times \frac{C}{100 \times A}\\ \\ H = \left( \frac{D}{E} \times 100 + \frac{F}{G} \times 100 \right) \times A\\ \\ I = H \times 1.25

乳児

　乳児については目安量となります．0-5 ヶ月では 9.83 g/d であり， 6-8 ヶ月では　12.5 g/d であり， 9-11 ヶ月では 22.0 g/d です．人工栄養児の目安量は 0-5 ヶ月では 14.0 g/d であり， 6-8 ヶ月では 15.2 g/d であり， 9-11 ヶ月では 23.8 g/d です．

妊婦

　妊婦ではたんぱく質の付加量を最終的な体重増加を 11.0 kg と仮定し，体カリウム増加量から間接的に算定します．妊婦の付加量の推定平均必要量は初期は 0 g/d であり，中期は 4.51 g/d であり，後期は 18.98 g/d です．妊婦の付加量の推奨量は初期は 0 g/d であり，中期は 5.64 g/d であり，後期は 23.73 g/d です．

授乳婦

　授乳婦の付加量の推定平均必要量は 14.04 g/d, 推奨量は 17.6 g/d です．1 日の平均泌乳量は 0.78 L/d であり，母乳中のたんぱく質濃度の平均値は 12.6 g/L です．食事性たんぱく質の母乳たんぱく質への変換効率は 70 % です．

不可欠アミノ酸

　不可欠アミノ酸（必須アミノ酸）の推定平均必要量は下記のとおりです．

不可欠アミノ酸の推定平均必要量 2015 年版
His Ile Leu Lys SAA AAA Thr Trp Val Total
組織アミノ酸パターン 27 35 75 73 35 73 42 12 49 421
維持アミノ酸パターン 15 30 59 45 22 38 23 6 39 277
たんぱく質必要量 (g/kg/d) に対するアミノ酸必要量 (mg/kg/d)
年齢 維持量 成長量 His Ile Leu Lys SAA AAA Thr Trp Val Total
0.5 0.66 0.46 22 36 73 63 31 59 35 9.5 48 376
1-2 0.66 0.20 15 27 54 44 22 40 24 6.4 36 267
3-10 0.66 0.07 12 22 44 35 17 30 18 4.8 29 212
11-14 0.66 0.07 12 22 44 35 17 30 18 4.8 29 212
15-17 0.66 0.04 11 21 42 33 16 28 17 4.5 28 200
18- 0.66 0.00 10 20 39 30 15 25 15 4.0 26 183
評点パターン (mg/g protein)
年齢 His Ile Leu Lys SAA AAA Thr Trp Val Total
0.5 20 32 66 57 28 52 31 8.5 43 336
1-2 18 31 63 52 25 46 27 7.4 41 310
3-10 16 30 61 48 23 41 25 6.6 40 291
11-14 16 30 61 48 23 41 25 6.6 40 291
15-17 16 30 60 47 23 40 24 6.4 40 286
18- 15 30 59 45 22 38 23 6.0 39 277

参照：
日本人の食事摂取基準（2015 年版）たんぱく質 (pdf)
日本人の食事摂取基準（2010 年版）たんぱく質 (pdf)