1. How are your child's vitals? Is there anything to be concerned about in the physical health department? I have friends who put their themselves & their kids on "healthy diets" (mainly a misunderstood approach to veganism with zero fats...not just low fat, NO fats) and nearly got their kids taken away because the kids were horrifically skinny & were having issues. That's not to say that fruit can't work for kids, but do your parents think you're starving them, or are they actually having visible issues? Anne Osbourne keeps her kids on a fruit-based diet & they seem to be doing pretty well, so it's definitely possible:
2. Are you adverse to letting your child make up their own mind about what they want to eat? I'm a big fan of leading by example & letting others choose their own path. It's obviously a bit different with kids, but my approach is offer, don't force. Otherwise you have a long road ahead of you fighting your partner, your parents, and other people in regards to feeding them when you're not around. I would suggest a compromise, if you're open to it - you feed your child your diet when you're around, and don't stress about it the rest of the time. Relationships are about compromise, not being a dictator, even if you feel like you're in the right...which of course makes life difficult when you're really passionate about something & your partner isn't.
That's not to say that getting everyone onboard with your chosen dietary path is impossible...my family has crazy food allergies, so I have to be ultra-diligent about what is eaten & what is touched because otherwise it's an Epipen & trip to the emergency room - I know exactly what you mean about people feeding them stuff when your back is turned. And it's the same old conversations with other parents at school & other social events who are clueless about how bad food allergies can be.
But it does feel endless at times because not everyone you come in contact with takes the situation seriously. So speaking from that perspective, you kind of have to decide how much control you want to exert...a compromise will make all parties the most happy; doing it only your way will probably be an uphill battle until your child grows up & moves out from your influence, which can cause endless frustration. I've seriously considered homeschooling because of the allergy issue in my household, that's how frustrating it is sometimes!
Also, on a tangent, I've been curious about the fruitarian diet claim that you don't get sick anymore. Not that I get sick that often, but I haven't had a cold or anything for the past six months since I started this diet. Even when everyone at work came in with severe colds (I work with a lot of workaholics who would rather infect people at work than stay home & heal haha), I just kept munching on my clementines (Vitamin C!) & felt great! Anyway, Loni Jane Anthony (of HCRV pregnancy Internet fame) posted a photo on her Instagram account a few months ago about a kid living a raw, plant-based diet and has never been sick or had to go to a hospital:
Sounds like a great benefit of this diet to me!
I hear you. I had a foreign neighbor growing up who only fed her kids fruits & veggies; her kids NEVER got sick when all of the other kids in school got sick. Like EVER. I mention foreign because I didn't know any native-born American families who were doing anything like that with their kids...period. Zero. Even to this day, I know very few families who eat close to nature. I am a big fan of the "whole foods" diet; that's not to say I hate processed foods, but most people feel better eating closer to nature.
Are you 100% raw? Since you don't want to compromise on other parts of the kid's diet, it may be worthwhile to compromise on a cooked vegan & gourmet raw meal plan instead of say a full-on fruitarian diet. Speaking as a male, if someone else prepares the food for me & it tastes awesome, I'm going to eat it, regardless of whether it has meat, vegetables, sawdust, or chemicals in it. Generally speaking, guys run off convenience & taste, so if you're willing to provide foods compatible on your diet for them - meals that are pre-made & ready to eat, and and that also taste amazing - things will probably work pretty well without having to get drama involved.
Basically, just kind of run the show invisibly in the background. Please note that I'm not trying to make this into a patriarchal society issue or anything where "the women stays at home to make the food", I'm simply pointing out that people are generally lazy when it comes to food preparation, so if some else hands us a plate of food that tastes good, that we also don't have to make ourselves, that food generally gets eaten, haha! So it's kind of an opportunity in disguise. You most likely won't be able to make it work 100% of the time, but even 90% is better than 50% if your goal is to fill your kid's diets with as much healthy fruits & veggies as possible.
For example, I brought an omnivore buddy to a raw workshop recently where we did stuff like raw falafel (dehydrated) & walnut greenstyle tacos...his comment was "if vegan food like this was available all the time to me, I'd definitely go vegan!" - that's how good it tasted! He's not a huge cook & typically sticks to very specific recipes, so while he won't be converting over anytime soon, that just goes to show that tasty food is tasty food & you can pretty much get anyone onboard if you're willing to put in some effort into daily meal preparation. So there's some food for though to help you with your struggles ;)