It's impossible for us to say whether your goal is practical or not, because we don't know how old you are, plus you left out a lot of other pertinent information...
I sounds like you plan to skip lunch every day and it's a long time between breakfast and dinner... have you planned for any healthy snacks to tide you over?
How many total calories have you budgeted for each day? If you don't eat enough calories, your metabolism will slow down because there won't be enough food coming in to sustain your body.
How much protein, carbs and fat? Some sources say you should get approximately 50% of your calories from carbohydrates, such as veggies and whole grains; 20% from protein, such as meats, eggs, dairy and legumes; and 30% from healthy fats, such as coconut and olive oil, avocados, nuts, seeds, etc.
What are the sources of your nutrients? Have you considered whether you will be getting adequate vitamins/minerals from your food or are you supplementing?
Typically, it's best to eat a larger breakfast and lunch and a smaller evening meal.
Hi Barb! I didn't realize I had left out so much information, and your comment got me thinking that my plan wasn't very well thought through. I usually don't eat breakfast because I'm in high school (16) so by lunch I eat way more than I should. Instead, I planned on eating fruit or a shake for breakfast and fasting for lunch. I wanted to intake a maximum of 1000 calories and burn just as much. I'm taking one a day vitamins for any missed nutrients. As far as healthy snacks, I was going to keep almonds with me to snack on.