What should i do here to help my boyfriend??

Me and my boyfriend are pretty in synch and know then the other person is off. Well the past 2 days we spent together he was more quiet than usual, and didnt seem as upbeat. Were both introverts, but hes usually more of the talker. But he wasnt talking a lot. I know he has some stress about work and wanting a better job. But hes also really stressed about his weight.. Hes not overweight or huge but he does want to lose some weight and tone up. During pillow talk i asked him why is there a distance between us, and whats wrong, and he told me hes insecure about his body and his weight. He has been going to the gym, and went today. Hes been eating healthier. And honestly he looked like hes lost a lot of weight already in just a month. But I can tell hes feeling insecure about his weight, his job, and maybe other things. What can i do to help him?? Hes still engaging with me, but you can tell hes distant and in his head about something overthinking. We just spend 2 days together, were not gonna see each other tonight bc hes taking a mini trip somewhere in the morning early but we will be calling and playing a game online together. For reference hes 30yrs old. I think hes doing great in life but hes hard on himself. And i can relate because im the same way, were very similar. But how can i help him?

I was thinking of sending a text like “i love you babe, and try mot to stress too much about everything. Just focus on the 24hours ahead of you” or something like that. Hes always supporting me, and i just want to be there for him. Ive never been with someone who struggled so much with body image, weve been together over a year btw. And hes been talking about his body insecurities more