To suggest weight loss in Engpsh, you could say something pke:

"Have you considered trying a weight loss program or diet to help you reach your health goals?"
"I think it might be a good idea for you to focus on eating healthier and exercising more regularly to help you lose weight."
"If you're interested in losing weight, there are plenty of resources available to help you get started, pke joining a gym or consulting with a nutritionist."
"One way to achieve your weight loss goals might be to set small, achievable targets for yourself and track your progress along the way."

It's important to remember to be sensitive and respectful when suggesting weight loss to someone, as body image and weight can be sensitive topics. It's also important to recognize that everyone's bodies are different and that there is no "one size fits all" approach to weight loss.