I actaully lost wieght once by just drinking water and having small things to eat throughout the day. I didn't know why until later why I did lose weight this way, but now that I try to do it again I can't.
So I have decided to eat according to my activity for the day. If I don't do anything I just eat 1 meal(supper), I still exercise and walk both dogs.
If I have small amounts of activity I eat a healthy breakfeast and 1 meal.
If I have large amounts of activity I will snack that day while following the small activity meal plan.
This with the new dumbell exercise plus walking two dogs at good walking pace for 20 minutes going up and down hill should help me lose weight right?
Small note - it's a little more in line to match exercise with what you ate the day before, because that's what your body's working on trying to burn. So if you're lazy one day, it's not the food you ate that same day that's not going to get burned, it's the food that's in your intestines from the day before.
And the answer to your question "Can a passive exercise/diet plan help me lose weight", is - it depends on your age and your sex.
If you're a man under 20, definitely. If you're a man under 30, possibly. If you're a man over 35, probably not.
If you're a woman under 20, yes. If you're a woman between 20-30, possibly - edging towards no after 25. If you're a woman over 30, no - and if you're a woman over 40, not even close.
Younger you burn calories more naturally, and men's bodies do it more efficiently than women's (in general).
But to make a note of one thing you mentioned - eating a healthy breakfast is great, but a 1-meal day isn't the ideal strategy for weight loss. When your body gets food once a day, it stores fat because the rapid swings in your glycogen and insulin levels prompt your body to store fat "just in case" a meal isn't forthcoming (old evolutionary trick we learned). Eating smaller meals 2 or 3 times a day (or even more than that) is the best way to maintain a healthy weight, because it keeps your insulin levels from fluctuating too wildly and your metabolism stays at a nominal pace instead of jacking up and down when you're eating / not eating.
Eating large number of small meals is, incidentally, ALSO the ideal way to GAIN weight if a person's on an intense muscle building workout, bc the end goal in both weight loss and muscle weight gain is the same - consistently high metabolism and low fat storage.