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Summary Scientists claim protein activates the cells responsible for keeping us awake and burning calories.
If you have a choice between jam on toast, or egg whites on toast, choose the latter, say scientists who have found that protein, not sugar, activates the cells responsible for keeping us awake and burning calories.The finding has implications for understanding obesity and sleep disorders.Wakefulness and energy expenditure rely on “orexin cells”, which secrete a stimulant called orexin/hypocretin in the brain.Reduced activity in these unique cells results in narcolepsy and has been linked to weight gain.Scientists at the University of Cambridge compared actions of different nutrients on orexin cells. They found that amino acids - nutrients found in proteins such as egg whites - stimulate orexin neurons much more than other nutrients.Previous work by the group found that glucose blocks orexin cells (which was cited as a reason for after-meal sleepiness), and so the researchers also looked at interactions between sugar and protein.They found that amino acids stop glucose from blocking orexin cells (in other words, protein negated the effects of sugar on the cells).These findings may shed light on previously unexplained observations showing that protein meals can make people feel less calm and more alert than carbohydrate meals.The study has been published in the 17 November issue of the scientific journal Neuron.
