If your focus is on strength, more weight and fewer repetitions makes sense. MAKE sure that you can complete at least 8 reps - if you can't you are using too much weight. If you are doing 3 sets, you may not be able to fit all the major muscle groups into 1 workout. Never work the same muscle group two days in a row because the muscles need at least 24 hours to recover. To really see results, you must decrease your body fat.
Many people confuse body fat with obesity.
Body fat is the percentage of fat that you store in your body as opposed to lean muscle mass. There are very thin people who have too much body fat because they do not exercise. There are also average to above average sized people who have very little body fat and are all muscle. At this fitness level, if you exercise aerobically 3 times per week for at least 30 minutes , you will see more results from your strength training. In addition to aerobic exercise, you should also do some form of stretching.