"As much as they could" is usually way too much. Adult veileds can eat dozens of insects a day. They can maintain weight, even gain weight, on just a few insects every other day.
I feed my females every other day, 2-5 insects, depending on the size of the insect. That's it. They become receptive, mate and become gravid. I then increase feedings, slightly, to ensure they don't lose body mass. Typically, my females have laid between 30-45 eggs, with the first clutches being larger (I am hesitant to restrict food on a growing animal). The average clutch size, after the first clutch, is usually around 30. Females that lay smaller clutches usually come out of it looking good. No sunken eyes, excessive loss of body mass (excluding the obvious!), and no nutritional problems.
Females that lay giant clutches of eggs (50+) have a harder time throughout the ordeal, from developing eggs (it take a lot out of them - literally), to getting about, to actually digging and laying them. Oftentimes, the por things are skiny, dehydrated, and suffering from calcium problems.
When they are healthy and not overfed, their bodies do not respond by developing huge clutches of eggs (an adaptation to exploit the "good times" in nature). instead, they produce a modest clutch, that does not excessivly tax the female's body.
In nature, the chances are they never lay clutches of 70, 80 or 100 eggs. Still laying larger than average clutches takes a toll on the female. They in effect, sacrifice their personal longevity in order to get more offspring out into the world. Similarly, if the climate's been harsh, they will hold off for a while, and develop fewer eggs. This is a more conservative approach - the female can live longer, and porduce eggs in a more favorable environment.
It also happens that smaller clutches tend to have larger, more robust eggs. Huge clutches have tiny eggs. The bigger eggs tend to produce larger hatchlings.
In captivity, things are different. Food is available in abundance not seen in any wild ecosystem. We must activly limit food to get the desired effects: If you want more eggs, and less long lived females, feed more. If you want fewer eggs, fewer times a year, and longer lived animals, feed less.
Most hobbyists that breed the animals for fun shoot for low numbers of eggs/clutches. Breeders that sell wholesale quantities of animals usually don't.