Dizziness is a symptom of a symptom of food poisoning. This sounds weird, but there is a reason this is true. Food poisoning often leads you to vomit and have diarrhea for a couple of days. Due to this, you become dehydrated. Even if you try to stay hydrated, for a good portion of this time, you will remain dehydrated. When one is dehydrated, you get dizzy.
This can be combated by trying to stay hydrated. As mentioned earlier, this might be futile for the first day or so of food poisoning. However, if you can keep it down for a few minutes, you will be able to get some of the hydration benefits. It’s recommended you drink some kind of sports drink in addition to water, since you’ll be low on electrolytes as well.