I think the safest answer is to use glass baby bottles instead. No one really knows what HDPE will do, and it is impossible to do the kind of study that could demonstrate safety for obvious reasons. There's no reason to believe that plastic would be safe, either. The plasticizers and other additives will leach out. See this article for example. Article Migration of plasticizers phthalates, bisphenol A and alkylp...

Please kindly see the reference:

Article Effects of medium chain triglycerides supplementation on ins...

The same study also discovered a lower rise in triglycerides and glucose with MCT oil, which may also influence the feeling of fullness. Additionally, taking MCT oil has been shown to significantly reduce body weight and waist circumference.