Weaning formula and bottles at 1 year- is it normal to see a decrease in eating during this change?

Our pediatrician told us to begin phasing out formula and bottles over the next month (son is 1 year and a week old, 99th percentile weight, not a big solids eater, loves his formula and bottles). We have started to cut back on daytime bottles and only do formula bottles upon wake up, before both naps, and at bedtime for now. All other bottles we are stopping. So essentially we are going from 7 + four oz bottles to only 4 bottles a day. We are really encouraging water from all types of cups and trying to get him acclimated to whole milk (he is not a fan of whole milk so it's really just the water). He is still not eating much in the way of solid food despite this formula decrease- we are on day two of this change. Is this pretty normal? Will he start to eat more as he acclimates to these changes? If he is hungry, he will eat...right? We are offering three sit down family meals and snacks throughout the day. Water is always at reach. Just looking for some feedback. It's been really hard emotionally because I worry he will dehydrate or lack nutrients...thanks so much.