I started with the 21 Day Fix because I found the idea of the different colored food containers appealing since I'm a very visual person. For me, knowing what a proper portion size is and actually adhering to it are two totally different things. The containers forced me to eat much more mindfully.
The eating plan determines which calorie range you need to be in to get adequate nutrition while being maintaining enough of a calorie deficit to lose and then, based on what tier you're in, will outline how many of each type of container you're allowed for the day. For example, when I started I was in the 2nd tier and was allowed between 1500 - 1799 calories a day. That worked out to 4 red containers (protein), 4 green (veggies), 3 purple (fruit), 3 yellow (carbs), 1 blue (nuts or hummus) and 4 teaspoons for either olive oil. peanut or nut butters. Vegans especially are allowed an extra green container if you're still hungry and I took advantage of that several times. According to the plan, you eat 5 times a day. 3 meals, 2 snacks.
The exercise part is high intensity but every single exercise can be modified and the camera makes a point of focusing on the modifier, a middle aged woman, who obviously isn't yet in the best of shape. When I did the first cycle, I modified everything! I was in such bad shape that even the warm ups were overwhelming some days. It's definitely doable even with chronic injuries or pain. I have a really bad right knee but I was careful and finished the program without even a twinge.
After I finished the Fix, I bought Chalean Extreme which is more about resistance training although there are two days a week that are cardio. Like the Fix, each exercise can be modified and they feature at least one person in each session who needs to modify all the exercises.
Which one did you buy? I've been thinking about trying Turbofire after I finish Extreme but I have a few months to go before I need to decide that.