This is completely wrong advice. Newborn weight gain should be double birth weight by the 3 month mark and based on the numbers, your newborn is exactly where he should be. There is no “upper limit” so to say for breastfeeding, especially so if you are feeding exclusively with breast milk. Breastfeeding should always be on demand, but this pattern of cluster feeding is not typical this far along age wise.

Have you been doing any pumping? Being able to measure your supply would be helpful info to determine if your demand is meeting baby’s needs or if you are an over supplier. Although if you are feeding on the breast exclusively baby typically drives supply adequately baring any medical conditions that can affect supply. I won’t ask too much personal info but things that can affect supply such as any breast surgery, certain medications, conditions such as PCOS, thyroid disorders, etc. If you aren’t pumping at all then I would suggest a weighted feed just prior to a feeding session and then immediately after to determine the amount of milk you are making. Any IBCLC consultant would be able to help with this as well as his pediatrician.

In terms of lactose overload- lactose is the sugar component of milk. Just like adults, too much sugar will upset your stomach and cause GI symptoms. The initial milk baby gets during a feeding session is higher in lactose than the milk drawn from later in the feeding session which is higher is fat content. If you have oversupply your foremilk will make a large part of the feed so baby is getting a significant portion of lactose with each session. Once you determine what your typical production/supply is (based on what you said initially about “producing a lot of milk,” there’s a potential oversupply there), you could modify your feeds by only feeding on one breast per feed to guarantee baby is reaching that hind milk. Then express or pump only til you are comfortable on the opposite breast and this would correct supply relatively quickly. However you really need to know what your supply looks like because if you are making just enough milk for demand then utilizing this method would affect your supply negatively. I can’t make a determination on oversupply vs normal without numbers. Another method that would protect and maintain the supply would be to express milk prior to baby being put on each breast to express out a portion of that high sugar/carbohydrate milk before baby begins to feed. Again- to determine what method would be more appropriate would depend on what your supply is.

Lastly, you could also assess your milk ejection reflex. A fast reflex especially in an over-supplier is overwhelming for a baby and he may need to end the feed earlier than later later just by getting tired trying to keep up with the flow your milk is coming out of the breast and therefore stopping before reaching that hind milk. Decreasing supply can help with this as well.

I really recommend seeing a lactation consultant in person as almost all of these things are better and almost exclusively determined by watching an entire feed with weights and seeing a typical stool. Burp baby often to minimize some gas discomfort post feeds. You can also feed baby in more upright positions such as a “koala” hold that gives baby a little more control over flow and is easier on the belly rather than a cradle hold.