Editing Calorie restriction (section)

===Minnesota Starvation Experiment===
The [[Minnesota Starvation Experiment]] examined the physical and psychological effects of extreme calorie restriction on 32 young and lean 24-year-old men during a 40% reduction in energy intake for 6 months. The study was designed to mimic dietary conditions during World War II. Participants could only eat 1800 kcal per day, but were required to walk 5 km per day and expend 3000 [[calorie]]s.<ref name=":1">{{Cite journal |vauthors=Most J, Tosti V, Redman LM, Fontana L |date=October 2017 |title=Calorie restriction in humans: An update |journal=Ageing Research Reviews |series=Nutritional interventions modulating aging and age-associated diseases |volume=39 |pages=36–45 |doi=10.1016/j.arr.2016.08.005 |pmc=5315691 |pmid=27544442}}</ref> The men lost about 25% of their body weight of which 67% was fat mass and 17% fat-free mass.<ref name=":1" /> The quality of the diet was insufficient, as it was intended to accurately represent the diet during war due to the inadequate consumption of protein, and a lack of fruits and vegetables. Despite the extreme calorie restriction, the experiment was not representative of true calorie-restrictive diets, which adhere to intake guidelines for [[macronutrient]]s and [[micronutrient]]s.<ref name=":1" /> Chronic weakness, decreased aerobic capacity, and painful lower limb edema was caused by the malnourished calorie restrictive diet.<ref name=":1" /><ref>{{Cite book |title=The biology of human starvation (2 vols). |vauthors=Keys A, Brožek J, Henschel A, Mickelsen O, Taylor HL |publisher=Univ. of Minnesota Press |year=1950}}</ref> Emotional distress, confusion, [[apathy]], depression, [[hysteria]], [[hypochondriasis]], suicidal thoughts, and loss of sex drive were among the abnormal psychological behaviors that occurred within six weeks.<ref name=":1" />