Underweight 11 year old - strategies

[Saisong]

DS is 11 and a pescatarian (by choice), not a great eater. Likes fish, tofu and cheese, but avoids eggs, pulses, nuts (and meat obvs) and not great with carbs.
We check height and weight occasionally - just for interests sake, not an obsessive thing. He is a skinny thing - visible ribs from front and back, and I had noticed he was looking more lanky than before. So he has added about an inch in height in the last 3 months, but actually lost weight. BMI on kids scale has tipped into underweight. I'm wondering if anyone has any good ideas on how to get him to maintain weight/foods to try.
Activity wise he is not great - loves his screens and games. However we make sure he has outside time every day - gardening/walks etc, plus he plays hockey and pre covid did athletics.
I'm worried about protein intake to make sure he grows properly in the puberty stages - he is, and always has been, on the smaller side of average - about 25th percentile. However comes from a tall (if lanky) family.

I may be worrying unnecessarily, but seeing his shoulder blades protruding this evening really made me pause

What about smoothies? I make DD aged 12 smoothies for breakfast and I put some yogurt in them as well as full fat milk...she's also boney.

Second smoothies. Would be concerned about avoidance of carbs unless they cause gI issues. Eliminating an entire food type like that is not healthy in a growing child. Also would add avocado to the diet.

Actually smoothies is a great shout. We don't have a blender, so that may be why it didn't occur to me. Easy enough to rectify and the novelty value will probably appeal to him. Yoghurt and oats would be good additions.
Also full fat milk for him - another blind spot for me as we use semi-skimmed.

He is funny with carbs - will eat chips, roasties and the odd (loaded) baked potato. Eats sweet potato under sufferance. Doesn't like lots of pasta but will eat if lots of sauce. Dosnt like 'raw' bread but will eat cheese toastie. Actually eats brown rice happily. A fussy bugger in other words - like most 11yo!

Fortunately he eats most veg and loads of fruit so nutrient wise I'm not too worried, plus he takes a multi-vit. Unfortunately avocado is one thing he will not tolerate.

I think what I'm struggling with most is that his nutritional needs seem to be different to the rest of us. We eat healthy enough, but i need to focus more on his specific needs.

How do you cook his fish? Using oil or butter in the cooking would increase his calories. I would tend to steam or bake fish so that it's healthy, but you could shallow fry it or wrap it in some greaseproof paper with olive oil and herbs or butter and garlic or similar and bake in the oven.

I think it would be worth speaking to the GP about the food avoidance. That's quite an extensive list. What's the source of it?

Re pasta, is there a specific shape he likes best? So you might have spaghetti but he could have macaroni?

How about nuts if he wont eat avocado?

Can he cook? Mine will eat more things if they cook them with me.

I had one like this and they are still pretty much the same as an adult. They still live at home. Smoothies are your friend. Mine doesn’t make theirs cow milk based but instead a high protein plant milk, add some natural Greek yoghurt, some protein enhanced cut oats and handful of fruit to taste with a small dab of honey. There are some combinations where a bit of peanut butter in it also works.

Should have added a blender never worked well here, too much faffing around but all the kids used a NutriBullet no problems since they were teens.

I do cook fish in oil/butter, sometimes breaded and baked. We eat fish maybe twice a week - any more and he starts refusing!

He's always been on the fussy side, we've tried not to make a big deal of it - no insisting on empty plates or tempting with pudding. Actually we don't eat much pudding, but that could be a way of increasing carbs - he will eat crumble/cake funnily enough.

I'm pretty sure a lot of it is to do with texture as much as flavour - eggs is definately a texture thing, as is beans (will not eat a bean in any form). Lentils I can squeeze some in as an extra ingredient. Actually the aversion to meat is probably texture related too. Oddly enough he would live off halloumi if we let him - you'd think that would be the wrong texture too (I worry about the salt though)

I hadn't considered going to the GP because the extreme skinnyness is a pretty recent thing. No doubt it is exacerbated by the growth into puberty (no other actual signs yet). I think I need to up his portion sizes and add more opportunity for (healthy) snacks. Sadly nuts are totally off his list otherwise peanut butter would be a good addition.

Thanks for all the suggestions so far - it is really helping me change my mindset.

Can you give an idea of what he would usually eat in a day?

I knew a few kids growing up that used vegetarianism etc to hid their eating disorder, so that would be where my head goes first.

I think at 11 you can have a frank conversation with him. He will be learning about healthy diets etc at school.
Do a bit of research together about what his body needs at this stage of his development.
If he want's to be a pescatarian then he needs to eat properly.
Tell him that he needs to find decent work arounds for his food avoidance items.
It's fine to not like certain things but if his body needs them he needs to accept an alternative.

You are right he is old enough to start to understand proper nutrition - and we have talked about it, except that he still won't even attempt to try the things he refuses. He enjoys cooking with me, but still won't eat things he makes. However we could explore the food he is happy too eat and see what might need increasing to give him a better balance.

Honestly he does eat, we have a well established repertoire that minimises the refusals. He is a very slow eater - is often still at the table long after I have finished and cleared up after! Which I think means his portions are perhaps not big enough (otherwise he'd never be done). I think he is more a grazer by nature, and perhaps I should accommodate that more.

I hear what you are saying about hiding an eating disorder, but I don't think it is that extreme. I think he is only tipping into underweight now because of the beginnings of teenage growth spurts, he needs to up his calorie intake clearly. I remember my brothers as teenagers being bottomless pits - they would fill up on bowls and bowls of cereals and sandwiches by the bucket load!

A typical day for DS would be
Bowl of cereal with ss milk (there are about 3 types he will eat, all multigrain types)

Lunch
Cheese toastie/Cheese pitta/cheese roll (he will eat the odd bread roll) or veggie sausage roll
Chopped salad veg
Yoghurt
The one school lunch he will eat is fish & chips

Afternoon snack
Crackers & cream cheese or similar and a piece of fruit

Dinner something like:
Spag bol (veggie mince features quite a bit now I think about it), lasagne, Fajita type wraps with lots of cheese and veg, pan-fried fish filets on noodles or rice, roast veg and halloumi with rice, stir-fry with braised tofu, veggie sausages & baked potato, salmon pasta (light on the pasta), puff pastry tart with spinach and feta. Sometimes he will eat quiche if it has more filling than egg.
If I add chips or sauteed potatoes he will eat them happily enough.

We don't often eat pudding, but he will top up with fruit/Yoghurt or a small pot of shreddies if still hungry.

I don't think it sounds too bad - however he probably needs bigger portions and maybe more nutritious snacks.

Definitely switch to full fat milk. Would he have it as a drink too? Maybe at bedtime? Also make sure the yoghurt is full fat, not the 0% stuff. Full fat Greek yoghurt is great. Rice pudding or custard might work too.

Hummus or a creamy dip to go with the chopped veg.

Extra grated cheese on everything, or extra olive oil drizzled over.

Our youngest has always shown signs of orthorexia.

Just be mindful of the food rules, OP. It can be a slippery slope very quickly, and going into puberty isn't a good time to be starving their body of certain nutrients.

I'd chat to the GP and ask for a dietician referral. Specialist advice early on (even if it's just for you) can be a lifesaver.

You've had some good advice above about smoothies/juices. And add protein powder (you can get an oat powder that's very tasteless and not noticed). Protein pancakes are good breakfasts, with greek yogurt and blueberries.

As he's 11 he's probably old enough for you to read this and then have him read some of it, like the amount of calories he needs according to his activity levels and how to achieve that in a healthy way.

I would be concerned about any teen avoiding carbs and think a referral to a Dietician as the PP suggested is a good idea.