Summarize this article in one sentence.
Gaining weight when you're pregnant is natural. For the first six weeks following childbirth, take it easy. Don't attempt to lose weight right away. If you lose weight too soon, it can take longer for your body to recover from childbirth.  If you're breastfeeding, give yourself at least 8 weeks, or 2 months, to recover. Your body may naturally shed the extra pounds when it's ready. Breastfeeding helps with this natural weight-loss process. When you're ready to start losing weight, take it slowly. You can easily reduce your daily food intake by 500 calories through eating smaller portions, swapping high-calorie foods for lower-calorie options, or skipping high-calorie food choices altogether. Switching from high-fat sweet coffee drinks, such as caramel lattes, to plain coffee or espresso, or substituting water for sugary sodas, will help make the weight loss easier.  If you're breastfeeding, losing weight too quickly can interfere with milk production. Talk to your medical care provider to find out her recommendations before starting any weight loss or exercise program. Lay on the floor or a firm mattress, either on your side or your back. Bend your knees, so that your thighs are perpendicular to your torso. Take a deep breath in, then as you breathe out tighten your pelvic floor muscles. Then, gently pull your belly button in and up. Hold this pose for 10 seconds, then slowly relax. Wait for 5 seconds, then repeat the exercise. Make sure you continue to breathe throughout.  If you've had a caesarian section, you may feel some gentle pulling in your muscles. You shouldn't feel any pain while doing this exercise. If you feel any twinges, sharp stabbing pains, or other discomfort, release any tension in your muscles and relax your body. Postnatal yoga classes can be a great way to learn new poses that will strengthen your pelvic floor and your abdominal muscles. In addition, yoga classes will help you expand your breathing which will help with the fatigue often experienced by new mothers.  Make sure you strengthen your pelvic floor before working on your abdominal muscles. The company of other women experiencing postpartum weight gain may also be a helpful support to you during this time. Pushing a stroller is a great exercise, and your baby will enjoy it too. Remember to keep your back straight as you walk, which will firm your belly muscles.  Remember that your joints and ligaments are looser than they were prior to your childbirth, so be careful of straining them. Women who combine exercise with lower-calorie diets had the most success of losing belly fat during research studies. After your lochia (postnatal bleeding) has stopped, you can return to the pool. If you've not been including swimming or water aerobics classes in your exercise routine, this might be a good time to try it. Swimming and water classes are good for your whole body, and don't stress your joints the way weight-bearing exercise does.  Many water classes have options for including your young child. Check with your local gym or pool for more information. If the gym doesn't have a class that includes your child, it might offer child care. Some health care providers recommend waiting as long as 5 months before engaging in high-intensity aerobics or running. This will allow your pelvic muscles to heal from childbirth.  Check with your medical care provider about what your own health situation is like before starting to do more strenuous exercise. Walking, swimming, and yoga are all examples of exercise that may be better options for your body during this time. Some women are able to return to pre-baby weight and shape, but many women find their bodies different after childbirth. You may find that you have wider hips, a softer belly, and a larger waistline.  Get to know your new, post-childbirth, body, and allow yourself time to adjust. Having a new shape doesn't mean you're unhealthy. Make the choices that fit into a new, healthy lifestyle for yourself and your new child.

Summary:
Wait 6 weeks before trying to lose weight. Eliminate 500 calories a day from your current diet. Do postnatal exercises to strengthen your pelvic floor. Try postnatal yoga classes. Walk with your baby. Try swimming. Wait at least 6 weeks before doing high-impact exercise. Be realistic.