Even if you will follow this "guide", this achievement is still hard to get, without doubt its the hardest of the game. I used this method that i consider the best for myself to get it.

Level 50 blue sparkle. It's without dubt the best sparkle to get this achievement thanks to it's quick absorb power. You will need the highest absorption level you can get to have some chanches to unlock the achievement.

The challenger sparkle absorbs nutrients faster than you. It's basically useless to move in another sector and try to eat as fast as you can. Even by using the blue sparkle's power, you will most likely end in getting around 70% of the nutrients, if you are lucky.
What can you do then? Given the fact you can't beat it by being faster, you want to limit your challenger's score as much as possible. Follow the enemy sparkle and "steal" its nutrient, eat the spheres its aiming at and use the fast absorption power as much as you can to catch the highest number of nutrients you can. Another trick i've used was to obstruct the sparkle by putting mine in front of it, blocking its way so it can't eat and increase it's score. This also would you give you some seconds to refill your power's bar so you can start to absorb a good number of nutrients instead of collecting them one by one.

Even if you will use this strategy, keep in mind it's not an easy achievement, It took me some tries to unlock it. Remember that, if you will beat the mission and not get the achievement you are forced to start the game all over again. You might want to backup your savefile once you reach Blue River so, if you will beat for mistake the mission you can simply replace your savefile with the old one and try again.