Because someone needs to. So here it is from me- someone who wanted to breastfeed and supports breastfeeding where reasonable, yet used and uses formula for medical reasons. Maybe that makes me a mostly neutral party. Maybe not.
First off- everything I learned about formula is self-taught or I learned from a Lactation Consultant. A good LC, on seeing that you want or need to use formula should be able to give you some pointers. Theoretically all formulas should be pretty much the same, brand name or budget. The WHO is supposed to regulate the ingredients and basic proportions. However-sometimes things are not so straightforward.
What you want out of a formula is to have it be whey based. Not casein based. You want the from birth formula. The follow-ons marketed from age 6 months + are not as well regulated and unnecessary (though they are often cheaper…). If your child requires supplementation beyond 1 year, full fat cow milk can be given (or mixed with formula if you are concerned about diet or intake).
Cow milk is recommended because growing brains need fat. If your child does not like cow milk to drink (mine didn’t), just be sure to supplement with other high fat foods alone or in cooking. Food such as- avocado, cheese, coconut oil or cream, peanut or seed butters, butter, cream, lamb, olive oils, and so on. For extra calcium try various vegetables like kale, alfalfa, etc and fish like sardines, salmon etc.
Back to formulas. Whey or milk solids should be the first ingredient. Maltodextrin is a common additive and should be around the 3rd-5th ingredient. It is sometimes seen as the first ingredient- this is not necessary and may make your baby eat more- its a carbohydrate that is digested quickly.
If you are combination feeding you do not need any special formula. Any birth to 12 month one that suits you is fine.
This sort of thing
Is straight up predatory marketing. I was always ambivalent about formula companies being big and bad and preying on the breastfeeding mother, but yeah. Not after seeing that. I’m pretty sure people are eating it up too. I’d hate to be more cynical but I’d imagine that if the one on the left cost more people would be paying for that too.
Let me reiterate: You do not need anything special to combination feed. No formula is better than any other. In fact less is often more.
Some reading on safe formula use can be found here http://info.babymilkaction.org/infant_feeding/formulafeeding