Enter your current weight and height into Slim Fast's "How Much Can I Lose" calculator (see Resources), as well as your goal date for losing weight. The website will calculate how much weight you can healthily lose in that amount of time.
Count how many calories you eat for a few days so you can calculate how much to exercise on the cross-trainer. The average daily intake for people with little physical activity is about 2,000 calories for men and 1,800 for women. If you're eating more than 2,500 calories per day with little physical activity, you'll probably have to trim your diet as you add in the cross-trainer to lose weight.
Wear comfortable clothing and supportive tennis shoes or exercise shoes and begin using the cross-trainer 15 minutes every day for a week. If you feel comfortable with that, add 15 minutes another time during the day.
Increase your time on the cross-trainer over the course of several weeks. A good goal for steady weight loss is about an hour per day, three to five days per week. Eventually, your goal should be to use the cross-trainer in one long period of time, such as an hour, instead of two half-hour periods.
Track your progress by weighing yourself weekly. Weighing daily isn't as helpful because your weight can fluctuate slightly with water and food intake. Be patient and stick with your plan.