Camilla Alves and Matthew McConaughey

The actor's wife Camila Alves says his shocking weight loss - which saw him shed 38lbs for his role as an AIDS patient in 'The Dallas Buyers' club - was a lengthy process she helped him with closely to make sure it was carried out safely.

Camila - who gave birth to their third child Livingston three months ago - explained: "It wasn't hard, it was a long process. It wasn't something that was done in a short bit of time. There was a lot of work put in and he was very disciplined. We made sure we had a whole system in place so it was safe."

"He was great, we had a funny dynamic because he was losing and I was gaining!"

Asked whether the couple's children - Levi, four, Vida, three, and Livingston - noticed the change in their father, she quipped: "They did, but it wasn't a big thing for them."

Now shooting has wrapped, the 'Magic Mike' actor is working on putting the pounds back on and Camilla has been feeding him healthy meals packed with essential nutrients to make the process easier.

She explained to Britain's OK! magazine: "He's good, were working on slowly getting him back to his normal weight. [I'm cooking for him], but I cooked for him to lose it too so its all part of the process."