I appreciate the hard work that people put into videos of this kind of thing, but some people just want to know where to go. Also, some videos are not in chronological order. This guide will tell you when and where to get each item needed to complete this achievement.
You start off with 100 health. Each booster you find gets you closer to the goal of 480, there are 27 in the original content areas. With the Definitive Edition update, it now lists how many Boosters are in an overland area. This is helpful if you know you are missing any.
The one on top of your Crawler only increases it to 107 (1).
The second one gets you to 125 health (2). It is in Pylon 512 in a room at the top of the ramp right before the Ringers.
The next one you can go after, if you want, is in the Brood Hive south of Pylon 512. When you enter the room with the drop off, look to the left. It's glowing and it will get you to 142 health (3).
Inside Cavern Rush, on the left as you approach the second big island, there is one that will get your health up to 159 (4).
In the Lonely Basin, as you are collecting six Cell Bots to open a big gate, look to the left as you approach the floating rings (ringers) that look like they are on wires. A booster there gets your health to 176 (5).
It's slightly lower than where you are standing when you get up to that point.
In the area of The Cradle with all of the quicksand and the submerged spaceship, carefully jump up to a jet engine above and right of where the tracks begin. This booster gets you to 193 health (6).
The next dungeon you can enter, once you get Seth, is the Repository Blitz dungeon. The booster on the way inside gets you up to 209 (7). If you can't quite get the jump right, come back with the FL1-R and glide into it from the other end.
The one inside, between two rollers, gets you to 225 (8).
Back in The Cradle, climb the big square building and drop off the right side to get your health to 241 (9).
You might want a bit more health before heading into the Foundry, and the Assembly has one at the end to increase your health to 257 (10).
Inside the Foundry, past the track rollers, you will find one up high on some crates that gets you to 272 (11).
After the Foundry, you can do The Crucible, and the booster at the end in there gets you to 287 (12).
The next one is through the nearby blocked gate after you get Duncan, inside a glowing rock (13).
Back in the Lonely Basin, near Pylon 512, is a rock to be broken that hides a button. You must dash across the button and dash through the gate across the way to get the booster that will increase your health to 316 (14).
Not too far from the big arm in the Shifting Sands is the Forsaken Halls dungeon. Three of the four Cellbots are near the entrance, the other one requires a lot of running away from superior enemies. You'll get a booster once you get to the end, it's under the ramp and gets you to 331 (15).
Near the big arm in the sand is a set of three tall rock platforms, the booster on top of the tallest one gets you to 345 (16). Directly east is another fast travel point. Follow the rocks and climb up when you get to the mountain to get a booster to 358 health (17).
On one of the rocks with one of the supports leading to Acid Marsh is a booster to get you to 372 (18) and you can get there from the nearby rocks. While you are here, you may as well do the Acid Marsh for another booster (key goal reward door) to get to 385 (19).
The one in the Obsidian Run is on the way through and hard to miss. It gets you to 398 (20).
The one in the Warren is just after you complete the FL1-R set. Head back to the upper right room on the map and get up to the center. Now jump over to the platform near the two pipes and go across the two pipes. There is a third pipe near some black spike crystals to increase your health to 410 (21).
Now that we have the FL1-R, it's time to go wrap up the loose ends. As you exit the Warren, go past the console and look on your left to get a booster to 423 health (22).
In the northeast are of the Lonely Basin, after you cross the huge chasm, a tall rock has a booster on top to get you to 435 (23).
In the Proving Grounds dungeon, the booster is at the bottom of the ramp and it gets you to 446 health (24).
The last three are found in the Coliseum at the end (to 458) (25), Armory Flux on a platform on the left in the second hallway (to 469) (26) and Tyrant's Forge at the end (to 480, of course)(27).
New Areas
With the Definitive Edition update, there are now even more Health Boosters to find. If you have the rest from this guide, they are not needed for this achievement. Nevertheless, I thought it would be nice to have a list. I'll update when I'm done.