There are different types of HIIT but an easy one to begin with is to simply warm up for 3 minutes on an elliptical machine or by walking.  Then work out for 30 seconds so that at the end of the exercise you feel satisfied.  Reduce the speed to slow down to a moderate pace.  Do this 7 more times or for total 8 intervals. Start with one interval and as your body is ready to take more increase the intervals.  Studies show that HIIT to be the absolute premier cardio for weight loss and optimal health as compared to longer, traditional cardio.
Ultimately, you need to pick a healthy eating plan you can stick to, Stewart says. The benefit of a low-carb approach is that it simply involves learning better food choices—no calorie-counting is necessary. In general, a low-carb way of eating shifts your intake away from problem foods—those high in carbs and sugar and without much fiber, like bread, bagels and sodas—and toward high-fiber or high-protein choices, like vegetables, beans and healthy meats.
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.