Don't rely on willpower to lose weight: these 2 things will make it easy and sustainable, according to a personal trainer who wrote a book on fat loss

Ben Carpenter/Getty

• The personal trainer Ben Carpenter said it's a mistake to rely on willpower to make healthy changes stick.
• For lasting fat loss, Carpenter advises making habits that can be kept long-term.
• Work with, not against, your existing preferences, he said.

If you want to lose weight successfully — and for good — it helps to make it as easy as possible.