As you have realised you cannot make a child of this age eat if he decides he is not going to do so. He is drinking plenty of the S26 Gold which is filling him up so well that he does not feel at all hungry. Short of trying to give him solids before the formula there is little that you can do. All the other formulas you mention above also have added vitamins and possibly essential fatty acids and other nutrients as well.
I am hoping that one of our regular forum members will be able to give you some advice which will be of benefit to you and your baby.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.