Fit, skinny 9yo vomiting after exercise - exhaustion?

[SoTiredSoTiredSoTired]

DS9 is extremely fit, runs 5km up/ down a steep hill before breakfast each day, does 30 minute swimming lessons that are laps of a 15m pool a few times a week. Eats large amounts, about 2/3 of what his very fit Dad eats. He has ADHD and is medicated, the exercise helps with everything, particularly running before meds have kicked in for the day.

He's also below 0.4th centile for BMI (98th centile for height, 9th for weight). After swimming lessons in the last few weeks he has been pale and has vomited on a few occasions. It looks like he's reaching very low blood sugar and is exhausted.

He's already eating about as much as he can fit in, volume-wise, he absolutely hates artificial-tasting or fatty food, and he is dairy allergic so all those protein breakfast drink things don't work.

Has anyone dealt with this kind of thing and did you find a solution that worked?

Agree it would be wise to check for T1 diabetes

@AnonyMumAuDHD the going pale and vomiting is at the end of the day, not the beginning. Point taken about meds working better with food, but if he physically can't eat until the meds have kicked in, there's not a lot I can do other than feed him when the meds have kicked in.

@dizzydizzydizzy Ok, so you did mean that... that's really interesting that your psych thought it was normal. I'd like to know more!

DS's developmental paediatrician and psychiatrist have each said independently on multiple occasions that while this profile of metabolism is one they've seen before, it's about 5-10% of the people they've treated. They both work in the public system and have worked in multiple hospitals in multiple countries.

The other dev paed and psychiatrist whom we've had to deal with in the past haven't believed us on how long the meds lasted and told us that we had no clue about ADHD, because the meds always lasted more or less the amount of time they were meant to. While these consummate professionals were what I might politely call self-serving, buck-passing idiots; the fact that they'd never encountered fast metabolizers in their large public hospital practice might indicate that fast metabolizers aren't necessarily the norm.

Re meds/food - my DD is the same - we now make and blend protein rich milkshakes from scratch and have one in the fridge to be shaken and sipped first thing with meds? You become really adept and knocking them up in under 2mins once you have got the hang of it. Would something like that be an option? We have a blender on the kitchen counter and throw fruit and full fat milk [plus some added protein/whey powder] etc in and, also, after trying a few [okay a LOT] of different brands of protein-added yogurt drinks/shakes we have found a few that she likes enough to have 100-150ml of with meds first thing?

Just coming in to offer solidarity on the underweight fast metabolism child front! I have one to (and was one myself). 75th centile height, just bobbing over 2nd centile weight. Always has, from birth. Very very active, eats well and just can't gain weight; it immediately translates into height. Also has what I call "energy crashes" usually the morning after a very busy day before. All investigated by Docs, no advice given as no obvious underlying cause and as not overweight, NHS not interested.

Mainly we deal with now by calorie loading at breakfast (cooked breakfast every day), never say no to food requests, try to cram in calorie rich food like nuts wherever possible and snacks (cheese and biscuits and fruit) just before bed. This has helped as hasn't had a "crash" for around a year now.

It's really hard work! And I'm constantly worrying about it. And people just don't understand skinny children unless they have them. It's not diabetes. It's not starvation. It's just them! And people are rude about it, suspecting neglect or whatever when actually it's the overweight children that need their concern!

Then, if my life is anything to go by, you hit 40 and the weight finally goes on and you're now constantly told "you look so well" or even asked if you're pregnant just because you finally have shape!!!

Just sending un-mumsnetty hugs.

@AnonyMumAuDHD good call, very sensible. Have tried that though (non-dairy versions) - it still makes him gag. He seems to just have to get used to the thought of having stuff in his mouth and stomach, which takes until the meds have started.

If you are under a paediatrician I would go back. 30 mins of swimming is not a huge amount / not endurance distance in the slightest.

I would have concerns about lactic acidosis, a metabolic issue, or some other kind of blood issue. Has he got any unexplained bruising, any headaches? It could also be environmental - something to do with pool chemicals.

Keep him out of the pool for a week and see what happens.

@Signoritawhocansway that's useful to know! I was like this as a child but it was always put down to me being born at 28 weeks' gestation and being short. Slower metabolism also eventually caught up with me!

@estrogone I agree the swimming isn't really the issue. I think he's so lacking in reserves that the swimming is the final straw. We need to find out what the reason is for the lacking reserves. Unfortunately he's no longer under the paed (who got burnt out and left the profession, and didn't get replaced), but will fight the utterly bloody useless GP to get some bloods taken...

I think I have a very similar profile to your son, ADHD more inattentive than hyperactive though, dyspraxia and very high metabolism. I still gag after breakfast everyday as an adult.
Can you add things like ground almonds to his meals to add calories? Or would he tolerate energy balls? My children love these made with dates, some kind of nut butter and cocoa powder usually.

if you google ‘most experienced ADHD psychiatrists UK’, the AI comes up with about half a dozen names, one of them being the psychiatrist I am talking about. She is now has a private clininic but until relatively recently was the lead consultant in charge of adult ADHD for one of the London NHS mental health trusts. She has ADHD herself, as do all her children. She must be around 60 so has decades of experience.

When we were first talking about taking medication last year, she told me that it says ‘10 to 12 hours’ on the packet leaflet but in her very long experience that was rarely (or never?) the case. She was not at all surprised when I told her I could feel the medication wear off in just under 4 hours. I’m taking Elvanse by the way, My DC2 is on Ritalin and she said the same to them. But of course we are adults. Could be different for children??? Or in who knows what other circumstances.

Then you have my deepest sympathies because my DD is very much the same. Just when we find something she thinks she can tolerate, she decides after a few days that she doesn’t like it any more after all (PDA profile, with some ARFID/food fussiness on the side), and she claims it makes her physically sick if she forces herself to eat something she is reluctant to. It’s exhausting. She’s 21 now and I am still banging my head against a wall, I think because I didn’t/couldn’t get any constructive help when she was younger. I’m an adult (obvs!!) so push through the nausea and, fortunately, DS doesn’t get these symptoms because not sure I could manage two of them with the same issue.

Watching this thread with interest now in the hope that someone will come along with some ideas that may help us too!

Is the trick to eat more in the evening then go to bed. Look at the food consumed in the day rather than at set times or particular food at set times. My DH eats a large one meal a day at 9pm then literally goes to bed. Personally I can’t do that at all id get reflux but it works for him. He can stomach an oat protein bar or banana sometimes after he’s been up 3hrs and had two black strong coffees. He runs a lot. With my DD I’d offer her anything to eat in the morning & not worry what it was, she had a phase of eating raw frozen peas and carrot sticks, then it was flapjack then it was a protein bar then a sausage roll, plain french bread, cheese or ham. Maybe not always the healthiest start but food=fuel and I look at the whole weeks intake to balance.. She’s a healthy bmi & her appetite also doesn’t kick in until the afternoon when she’s on her adhd meds.

I think first call is to ask for a meds assessment. ADHD meds are linked to appetite and metabolism so you need a review.

My dc is the same though, no meds. We found iron was a culprit.

Just going to add coeliac as something to get checked out.

Ds2 was diagnosed at 2, but vomiting and pale almost translucent skin were a thing.

You also mentioned your DS medication not lasting as long as expected and I wondered if it was due to malabsorption.

if you do go down that route don’t go gluten free until after the tests, as you need to have been on gluten for previous 6 weeks for the tests to show positive.