Nieuwenhuizen Arie G, Hochstenbach-Waelen Ananda, Veldhorst Margriet A B, Westerterp Klaas R, Engelen Mariëlle P K J, Brummer Robert-Jan M, Deutz Nicolaas E P, Westerterp-Plantenga Margriet S
Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, PO Box 616, Maastricht 6200 MD, The Netherlands.
Br J Nutr. 2009 Jun;101(12):1859-66. doi: 10.1017/S0007114508131774. Epub 2008 Nov 19.
Proteins are the most satiating macronutrients. Tryptophan (TRP) may contribute to the satiating effect, as it serves as a precursor for the anorexigenic neurotransmitter serotonin. To address the role of TRP in the satiating properties of dietary protein, we compared three different breakfasts, containing either alpha-lactalbumin (high in TRP), gelatin (low in TRP) or gelatin with added TRP (gelatin+TRP, high in TRP), on appetite. Twenty-four subjects (22-29 kg/m2; aged 19-37 years) received a subject-specific breakfast at t = 0 with 10, 55 and 35 % energy from protein, carbohydrate and fat respectively in a randomised, single-blind design. Hunger, glucagon-like peptide (GLP)-1, ghrelin, amino acid concentrations and energy intake during a subsequent lunch were determined. Suppression of hunger was stronger 240 min after the breakfast with alpha-lactalbumin compared with gelatin and gelatin+TRP. Total plasma amino acid concentrations were lower with alpha-lactalbumin compared with gelatin with or without TRP (from t = 180-240 min). TRP concentrations were higher after alpha-lactalbumin than after gelatin with or without TRP from t = 0-100 min, whereas from t = 100-240 min, TRP concentrations were lower after gelatin than after alpha-lactalbumin and gelatin+TRP. The plasma ratio of TRP to other large neutral amino acids (LNAA) was, only at t = 100 min, lower after gelatin+TRP than after the other breakfasts. Plasma amino acid responses, TRP concentrations and TRP:LNAA ratios were not correlated with hunger. GLP-1 and ghrelin concentrations were similar for all diets. Energy intake during a subsequent lunch was similar for all diets. Summarised, an alpha-lactalbumin breakfast suppresses hunger more than a gelatin or gelatin+TRP breakfast. This cannot be explained by (possible) differences found in TRP concentrations and TRP:LNAA ratios in the breakfasts and in plasma, as well as in circulating total amino acids, GLP-1 and ghrelin.
蛋白质是最具饱腹感的常量营养素。色氨酸（TRP）可能有助于产生饱腹感，因为它是厌食性神经递质血清素的前体。为了研究TRP在膳食蛋白质饱腹感特性中的作用，我们比较了三种不同的早餐对食欲的影响，这三种早餐分别含有α-乳白蛋白（TRP含量高）、明胶（TRP含量低）或添加了TRP的明胶（明胶+TRP，TRP含量高）。24名受试者（体重指数为22 - 29kg/m²；年龄在19 - 37岁之间）在t = 0时接受了一份根据个人情况定制的早餐，早餐中蛋白质、碳水化合物和脂肪提供的能量分别为10%、55%和35%，采用随机单盲设计。测定了随后午餐期间的饥饿感、胰高血糖素样肽（GLP）-1、胃饥饿素、氨基酸浓度和能量摄入量。与明胶和明胶+TRP早餐相比，食用α-乳白蛋白早餐后240分钟时饥饿感的抑制更强。与添加或未添加TRP的明胶相比，α-乳白蛋白组的血浆总氨基酸浓度更低（从t = 180 - 240分钟）。从t = 0 - 100分钟，α-乳白蛋白组后的TRP浓度高于添加或未添加TRP的明胶组；而从t = 100 - 240分钟，明胶组后的TRP浓度低于α-乳白蛋白组和明胶+TRP组。仅在t = 100分钟时，明胶+TRP组后的TRP与其他大中性氨基酸（LNAA）的血浆比值低于其他早餐组。血浆氨基酸反应、TRP浓度和TRP:LNAA比值与饥饿感无关。所有饮食的GLP-1和胃饥饿素浓度相似。所有饮食随后午餐期间的能量摄入量相似。总之，α-乳白蛋白早餐比明胶或明胶+TRP早餐更能抑制饥饿感。这无法用早餐和血浆中TRP浓度、TRP:LNAA比值以及循环总氨基酸、GLP-1和胃饥饿素中发现的（可能的）差异来解释。
