Remember the story in the Bible where God told moses to "send men to spy out the land of Canaan, which I am giving to the people of Israel" (Numbers 13:2). These 12 spies were dispatched in 1443 BC. After forty days these spies returned and reported what they had seen to Moses and the whole congregation. They said "We came to the land to which you sent us. It flows with milk and honey, and this is its fuit." However, there's a big HOWEVER here "The people who dwell in the land are strong, and the cities are fortified and very large. And besides, we saw the descendants of Anak there."
The people were discouraged. But this Caleb guy quieted the people in verse 30 and suggested eagerly to go up at once and occupy it, for they are well able to overcome it. The spies continued with their report saying "we seemed to ourselves like grasshoppers and so we seemed to them."
Below are photoshopped images that may be a good semblance of the Anakim.
I guess the Bible isn't exaggerating when it says Israelites were mere grasshoppers compared to the giant Anak's size. It's highly possible, many things have happened and evolved from the last 3,000 years.
The Israelites "raised a loud cry" (Numbers 14:1) and grumbled against Moses and Aaron saying "We should have died in Egypt! Or in the wilderness! Why is God bringing us into this land to fall by the sword?" (vv 2, 3). These people who complained were 20+ y.o. men that were part of the army. Because of their unbelief (after all the signs and plagues God shown in Egypt), God did not permit them to enter the promised land anymore. So they got what they wished for, to die in the wilderness. But then they changed their minds and rebelled once again saying "Okay! We'll go and fight them!" Well God wasn't with them anymore, so they lost.
The remaining Israelites were smaller in size which made it more difficult and quite impossible to drive out the giants. I guess God was at work again to prove His power. He has been using the faithful weak who holds onto nothing but Him to conquer giants. The greater the discrepancy between the weak and the giant, the greater view of His glory is revealed. That's God's amazing math! :)