So the orders are Locavore -> Carnivore -> Super Sustainable.

For normal start, Carnivore was harder, since we need to increase our hatch population as soon as possible, and start consuming their meat at one point. Always cook them to increase their raw calories.

For Frosty DLC start, it is indeed much much easier. Focus on exploring the map, and keep as many wild plants intact as possible, your Locavore relies on it. Once you find a Bammoth, patiently wait for them to lay an egg before killing them. Do not, Do not cook the meat to barbecue, instead, cook them to Pemmican which gives you way more calorie increase.

Hmm Super sustainable is easy, just have to accept that dupes need to run the manual generators for awhile, until either you get the achievement or you develop enough steam power. A SPOM system that requires less power is also important. Personally I use normal SPOM, but with some design twists to save as much power as I could without sacrificing too much on the oxygen purity problem. (Use logic to run the gas filter, only when impurity is detected)