This study is a gem.  I reference it all the time with clients.  The wealth of knowledge we gleaned from this research is invaluable. 

Nuts and bolts:

• Took place from 1944-1945 at the University of (you guessed it) Minnesota led by researcher Ancel Keys
• Studied the physiological and psychological effects of semi-starvation on 32 male volunteers
• 3 months control period, 6 months semi-starvation (taking in <50% of their control calories), 3 months refeeding
• Participants required to lose 19-28% body weight
• Rigorous physical activity

Some of the reported physical changes:

• Muscle wasting occurred throughout the body, including the heart
• The heart's functioning declined 
• Body temperature decreased along with metabolic rate (-40%)
• Edema (fluid retention) occurred
• Felt cold all the time and became physically weak and tired
• Orthostatic hypotension
• Muscle cramps
• Skin pale, dry, cold, rough, hair loss

And additional changes in personality:

• Increased apathy, depression, moodiness, irritability, feelings of ineffectiveness
• Decreased alertness, ambition, comprehension
• More neurotic traits, higher anxiety, rigid with rules
• Loss of humor and increased social isolation

They also became fascinatingly obsessed with food:

• Increased thoughts and talking about food
• Started reading cookbooks, collecting recipes and menus (in lieu of writing letters to their friends and family)
• Strong food cravings
• Possessiveness with food
• Wanted all food to be served very hot in temperature
• Meals drug out to as long as 2 hours during which they ate every morsel of food

If you are familiar with eating disorders, what you're probably noticing is that this sounds a lot like the traits and behaviors seen in someone with an ED.  Note that these were healthy men without ED's that participated.  What that tells us is that the effect of starvation itself causes a lot of the symptoms of the ED, and are thus resolved by refeeding.  We often tell patients that food is literally their medicine (and simultaneously the thing they are most afraid of).