No it is not okay, ALL of those items are really bad for you. Including the so-called "veggie" burger. Definitely not okay on a regular basis.
If you are stuck in a situation where you MUST eat at McDonalds, then just have the veggie burger and water, or a small hamburger and water. Chew it all very very well. Avoid the fries and cola, especially DIET cola (diet = super toxic). A slightly better idea is to get a salad and pick out any meat and cheese and eat it with no dressing or the tiniest bit of dressing possible.
The best solution is not to go to McDonalds.
You could make some pretty tasty veggie burgers at home using different vegetables, grains, and seasonings. Or just marinating and grilling a portabella mushroom.
Of course, if you really enjoy McDonalds, you can still have it, just make it a special treat, perhaps once a month or less. If that is the case, order those items you REALLY enjoy (real coke not diet), enjoy it thoroughly, and eat healthy food the rest of the time.
You might want to hang around curezone a lot so you can learn what truly healthy foods are.
Here are the ingredients of the McDonalds Veggie Patty:
Water, soy protein product, partially hydrogenated soybean oil, vital wheat gluten, modified cellulose, spices, salt, evaporated cane juice powder, hydrolyzed corn and soy protein, natural flavor (vegetable source), yeast extract, caramel color, vitamin B1 (thiamine hydrochloride), vitamin B2 (riboflavin), vitamin B3 (niacinamide), vitamin B6 (pyridoxine hydrochloride), vitamin B12 (cyanocobalamin), pantothenic acid (calcium pantothenate), reduced iron, zinc (zinc oxide).
Regular McDonalds Bun:
Enriched bleached flour (bleached wheat flour, malted barley flour, thiamine, riboflavin, niacin, folic acid, reduced iron), water, high fructose corn syrup, partially hydrogenated soybean oil, yeast, contains less than 2 % of each of the following: salt, calcium sulfate, calcium carbonate, calcium silicate, wheat gluten, soy flour, baking soda, emulsifier (mono- and diglycerides, diacetyl tartaric acid esters of fatty acids, ethanol, sorbitol, polysorbate 20, potassium propionate), sodium stearoyl lactylate, dough conditioner (corn starch, ammonium chloride, ammonium sulfate, calcium peroxide, ascorbic acid, azodicarbonamide, enzymes), calcium propionate (preservative). Contains wheat and soybean ingredients.