I (40M) am new to this whole scene because I wanted to lose weight. This is the first time I have ever really gained weight because my metabolism was always stupid high, but its slowed down in middle age as expected.
I started intermittent fasting, immediately cut out snacks and started having a Slimfast shake for lunch, then a reasonable dinner.
Thats all been fine, and my weight is starting to come down.
I did read articles saying that Slimfast isnt particularly good because of the sugar content, but all the articles seem to be from the US (I am British) and the stuff I have is no added sugar, and all that seems to be carb based.
People have suggested skipping it for a protein shake instead, but a lot of that is conflicting!
People have said about making a shake with protein and peanut butter, people have said peanut butter is awful for it.
I just dont know what to do and I am going in circles.
What can I drink at lunch that is better than I am currently drinking? Do I just mix the protein as directed? Do I add things?
OP, I just wanted to point out that this line from another comment is confidently incorrect. You do not need carbs. You may want them, you may even prefer them. But "need" is straight up wrong; our bodies operate just fine in a complete absence of digestible carbohydrates. You do, however, absolutely require healthy fats (saturates and monounsaturates; processed PUFA are seriously bad) and complete protein. Sources: "Good Calories, Bad Calories," Taubes; "Fat Chance" and "Hacking of the American Mind," Lustig; "Body by Science," Little and McGuff. There are loads of books you can read to get the answers to your questions rather than relying on Internet hearsay.
It sounds like, at least in part, sourcing is one of the issues with ingredients, and that you've been getting conflicting information because people leave out that context. Peanuts can be awful for you, but sourced with care, they're great! Oh, right, how do we know our food supply integrity? Well, now we're actually getting into the meat of the issue. No pun intended.
None of this answer your questions, and that was intentional. Also, sorry. But I did provide you with some excellent sources to start getting answers that are not a bunch of unsubstantiated Internet hearsay. You have one body, and it happens to carry your brain. Invest in it like your life depends on it.
Edit: wrong book title