If it's really NATURAL that you're going for...
I'll suggest doing an exercise plan to reap the most benefits - remember your body needs to rest and for muscle to repair, so I tend to do relaxing/meditating yoga or walk the dog for "Rest Day"s. Do a mix-up of work-outs that you enjoy - like Leslie Sansone 5 Mile Walk for days when you really don't feel like working out; Cardiovascular / Sculpting(kickboxing - Turbo Jam; 10 Minute Solution); Interval Training (Jillian Michaels, Kelly Coffey-Myer's New You Coming), Flexibility / Toning (Crunch - Burn & Firm Yoga Pilates blend; MTV Power Yoga). You get a good range to prevent boredom, and it helps you achieve toning and losing weight in all the right places. What's best is the endorphins you get from exercise - for someone who has NEVER exercised in 30 years, I can really put my foot where my mouth is. It is also amazing how your body adapts and transforms. My body's immune system improved tremendously, my insomnia eased, my moods elevated.
Within the first 45 minutes post-exercise that lasted 60mins or more, there is a “metabolic window.†This means that enzymes that replenish muscle carbs are at their highest levels. Plus, insulin, which rebuilds protein stores, is at peak levels. So eating a carb-and-protein mix (peanut butter sandwich, yogurt with fruit, bagel with cream cheese, or a handful of nuts) at this point will maintain muscle, replenish glycogen stores and reduce the amount of fat your body stores.
Missing the metabolic window is bad news: If you delay refueling, you slow carb replenishment by 50 percent and protein repair by 80 percent. And that means that you may be sluggish and fatigued during tomorrow’s workout. I personally like protein whey shakes (Optimum Nutrition).
Take foods that naturally boost metabolism like chilli, capiscum, jalapenos, curry (anything spicy - up to 8% increase), green tea, caffeine, iced water during meals (thermogenic process), grapefruit, yogurt, broccoli, oatmeal, soy milk, spinach, apples, turkey, beans, almonds. Opt for 4-6 small meals a day.
When I was really obsessed about working off the weight gained from excessive, extended steroid use for my asthma, I managed to lose 10kg in a month, and 10% body fat, bringing me to an althete's body fat percentage, with this 7-day plan - I wasn't even very fat to begin with, I could still fit into a S but am normally a XS. I couldn't even walk up the stairs without having to use my inhaler, so you do really feel good about yourself, your stamina, knowing your body is strong and capable of doing things like moving furniture instead of just looking thin for your wedding pictures. I think a positive and confident mindset shows in the way you look too, compared to someone who had starved themselves to their ideal weight. A really good article you can google for is "Burn the Fat, Feed the Muscle".
All the above workouts I mentioned are easy to find online and can be done in the privacy of your own home. Pick other stuff that you enjoy like bellydancing, salsa, hip hop - there's workouts designed for every interest. It's important to keep yourself motivated so the workouts should be fun. Even fancy gear helps, like new Asics shoes, a new yoga mat etc.
I only worked out for a month and can honestly say that it was "difficult" for me to gain weight months after, whereas my crash diets in the past always failed once my depravation kicks in and I binge. The high metabolic rate stayed for months after that ONE disciplined fitness regime but I've now slackened and am hoping to pick it back up soon (it's been more than 6 months since I last worked out~)
Take good care of yourself during this time too, it helps keep you on track - have a weekly food indulgence like the tiramisu you've been eyeing all week, weekly/monthly facials, manicures/pedicures, moisturise face and body every night, weekly body scrubs, collagen eye masks, hand masks, taking the time to read a book uninterrupted, splurging on a gorgeous coveted bag, etc - they all add up because they're all in line with a singular goal - it's all about making you feel good about yourself.
I know my post is long, but I really hope it helps you girls out there. It definitely did for me