Walking around with your baby strapped on to you in a carrier for hours is good cardio! You wouldn’t just let your baby cry, and holding them and carrying them around is free exercise!
Breastfeeding burns 400-600 calories per day! (Doing cloth diaper laundry burns even more!)
If you try to eat meals with people, the baby cries if you sit down for longer than 10 minutes so you automatically can’t eat dessert.
Never using a stroller means you burn more calories babywearing. Squatting down to pick things up is even more exercise!
Breastfeeding not only burns calories but seems to mean that your baby decides he wants to eat as soon as you heat up your food. Therefore, you eat less because your food gets cold and unappetizing.
You don’t own a baby swing, bouncer, walker etc, so instead you get extra exercise by rocking your baby, bouncing them in your lap, and holding them.
If your baby cries a lot and therefore possibly has allergies, instead of trying hypoallergenic formula you go on an elimination diet. It’s basically impossible not to lose weight if you’re avoiding dairy, gluten, nuts, and soy. Soy is in almost any processed food, so you have to cook everything from scratch which is great for weight loss. Also, you can only eat salad with no dressing or cheese at restaurants!
The fact that you don’t nap train means baby naps at random times, so by the time you prepare your food he wakes up and you don’t have time to eat.
Trying to eat while wearing your sleeping baby in a carrier eliminates entire genres of food from your diet like soup which could too easily spill on your baby, hot liquids, and crumbly foods.
Not using a crib may mean you get stuck sitting right next to your baby in your bed while he naps, so you can’t eat any foods that make noise (bag of chips etc) while he naps. You also can’t get up for seconds without waking him, so automatic portion control!