Getting sick when adjusting my diet

If you believe you eat so poorly that you are malnourished then you should definitely see a doctor.

This sounds kind of like refeeding. Your body has gotten so used to eating a certain way that it is completely accustomed to that. New stuff is a shock to the system

VexTheDingo876 wrote: »

So I eat very poorly, like In definitely sure I'm malnourished because I mostly eat junk and fast food.

Improbable that you're actually officially malnourished. Even junk food and fast food have some nutrients. Unless you have a serious (doctor-diagnosed) deficiency or deficiency-related health condition, there's no need to make a change instantly for health's sake.

Many Americans (my reference group, that I know most about) and probably other folks in developed-world countries likewise, are deficient in some micronutrients and fiber, but more like sub-par than literally "malnourished'. It'll be good to fix that, but it's not a 5-alarm crisis.

However anytime I try to buy something and start preparing better food with veggies and the like, I spend the next couple days feeling sick to my stomach. My rationalization is that my digestive system is just not used to having to work so hard since I usually eat garbage and now I'm giving it a real challenge.

Is that accurate or should I see a doctor to see if I need to try a different sort of diet protocol?

Best guess: Are you increasing fiber dramatically? That can do it, especially if you lowball fats and hydration at the same time. Extra likely, if you feel constipated - lower belly uncomfortable, etc. It can cause gas and bloating, too, or a sense of nausea (things sort of get backed up).

Another possibility: Did you start eating a lot of some common sensitivity-related food, that you didn't much eat before, like dairy, soy, nuts, eggs, yeast, gluten? (The last two are unlikely: Lots of gluten and yeast in standard fast food/junk food, usually.)

Anytime there's a notable change in diet, our gut microbiome needs to adapt. Research suggests that takes a couple of weeks or so. If there's a dramatic change, there can be digestive unpleasantness until that adaptation happens. (Gut microbiome: Several pounds of microscopic critters in your digestive system that are essential to your well being, but that aren't even genetically "you". They digest things we don't, turn them into substances we need. If we change diet dramatically, we need to develop a different population mix of those little guys. Some die off, we need new ones. To get new ones, consider probiotic foods in your mix: Live culture yogurt/kefir, unpasteurized sauerkraut/kim chi, unpasteurized vinegar, etc. You could even take a probiotic supplement, though that's sort of a shot in the dark.)

If you're going to make a dramatic change in what you eat, phase it in slowly (as someone above recommended). That will work better.

For now, go back to foods you ate before, even if you think they're fast food/junkfood/garbage so evil. (They're not that evil.) Keep it calorie appropriate if you can. Do that for a few days to a couple of weeks. If you still feel sick, see a doctor.

If you feel OK after going back to your previous way of eating, gradually add in some more nutrient-dense foods, and gradually phase out foods you want to reduce. Spread that over several weeks. If a problem occurs, notice what changed in your eating in days close to that time, like with a couple of days. Adjust accordingly.

Go slowly. You'll probably end up OK.