You can substitute chia seeds in place of other seeds in a recipe if you'd like. Chia seeds are a good source of fiber and provide omega-3 fatty acids that some seeds do not, however all seeds contains protein and other vital nutrients. I'd switch it up every now and then. Flax and hemp are also good options.
All you need to do is drop about 1 Tbsp into your NutriBlast as one of your boost options.
While I don't advocate calorie counting I do think it is a good idea to be aware of a general ballpark on how many might be in a typical Blast recipe that you make. We tend to not register how much we eat when we consume foods in liquid form. However, if you are using high fiber foods and including some protein and healthy fats, you will be more satisfied and most likely will ward off hunger for longer than if you just blasted high sugar fruits.
Chia seeds actually absorb 10x their weight in water so they help to thicken up your Blast making it more filling
For weight loss tips, I'd suggest searching "weight loss" for recipes and articles that can help you along your journey!