Wear a blood glucose monitor for a month or two. Don't make any changes whatsoever to diet or activity levels for the first 2 weeks.

Then change it up so you are taking a mile or two walk after every meal. Don't change your diet.

Note the difference in blood sugar levels. It won't happen for everyone but the difference just an extremely moderate level of activity makes - especially directly after meals - was actually one of my larger surprises doing exactly the above.

If I am diligent about my 10k steps/day, I find it difficult to put on weight unless I'm eating like total crap. Combine an effort to try to never eat simple carbs with the above walking regimine and most folks are going to drop weight faster than they would ever expect. Quadruple (or more!) true if you also add a GLP-1 to the mix.