Well I am no nutritionist or weight loss expert, but I think weight training will definitely help. What you do all day at work is active, yes. But if it's something you do all day every day, not only is your body is most likely adapted to it, but it also probably isn't intense enough if it's something you can keep up for sustained periods of time. You need to up the intensity. In my opinion, half an hour of super intense working out is going to have a bigger impact on your body than an entire day of walking. If you're short on time, I suggest doing your research on weight training, utilizing supersets (which will keep the intensity up, and make the workout faster, giving you more time!) and HIIT cardio. Remember the more muscle you have, the higher your metabolism, and the better your body is at burning fat and staying lean
so resistance training is really great for keeping a lower body fat %.
As for the diet, I personally wouldn't have so much fruit, carbs and starchy veg if I was going for fat loss. I know you have a job which requires energy throughout the day, but maybe think about cutting down on the rice, fruit and potatoes just a tad, especially later on in the day. Instead maybe try more leafy/green veg like cabbage and broccoli, and up the protein. For example, in the first post, I would ALMOST switch the meals around completely. I personally would keep breakfast the same, have the nuts as a mid morning snack, then the lentils rice and oats in the middle of the day (maybe replace either rice or oats for fibrous green or leafy veg, as you probably don't need two carb sources in the one meal...) more nuts for afternoon snack, and the 2nd meal for dinner, replacing the potato with a protein source (such as soy, tofu, wheat gluten, or "fake meat" product) Have the raw vitamin code after training and before bed.
I'm not a nutritionist or an expert, so make sure you know what you're doing or consult a professional before making any drastic changes
this is just what I would do personally.