It's important to realize that if you aren't sweating, you probably aren't working hard enough. If your heart rate isn't up (aka you aren't breathing hard), you most likely aren't burning very many calories. If you have been doing the same workout each day, or you've been eating the same "healthy" meals daily - let me guess - you're a) Bored & b) Not getting the results you want.
If that's you - it's time to challenge yourself. Change it up. Maybe this means cutting something out of your diet for a week - like no processed sugars for 7 days. Or maybe it means adding something - such as eating a bowl of mixed crunchy veggies (carrots, celery, bell peppers) each day.
Most likely though, you need to challenge yourself in your workouts. I recommend trying a new class at the gym (cycling, yoga, aerobics, etc) or creating your own circuit & completing it with 40 second "on" & 20 second "off" intervals. Or maybe even something simple like adding one exercise to your daily routine... like start jump roping each day for 2 minutes/day & go from there.
I challenge you to challenge yourself! Each week pick a new activity or a diet change that you would like to try & stick with it. Commit to something & keep it up. You can do anything for 7 days!