A diet or a meal higher in dietary protein has been reported to promote satiety and suppress food intake in humans in several previous studies. It was suggested that the presence of amino acid in the blood as a result of higher protein intake served as signals that suppress appetite in humans. More recently, it has been observed that incomplete or lower quality proteins, i.e. those missing one or more essential amino acids, may suppress hunger more than complete proteins, as the ingestion of incomplete proteins in the long term may lead to deficiency of essential amino acids. Plant proteins are generally considered incomplete protein when compared to animal proteins, which mean that plant protein may have higher appetite-suppressing effects.