Le'ts Weign-in on Atkins

Masterdo

Atkins causes massive water weight decreases, which affects electrolyte balance in your body.

Low carb diets offer no real metabolic advantage over carb diets. Eliminating carbs to lose weight is not really sustainable over a lifetime imo, and doesn't reinforce the fundamentals of weight loss and diet change. Which is IMO, moderation in what you eat over restriction.

Here is one for you to try on for size, supposedly the best bodyfat tests are hydrostatic, and bodpod. So lets say you are dehydrated how you said, you would have less water in your body, making you less buoyant in a hydrostatic test, which means you will come in at a lower bodyfat %. Same goes for bodpod, less volume under the skin = less bodyfat.

My point is, This is how people get to super low levels of bodyfat, it may not be pure fat, but water retention may play a keyrole in super low numbers under 7% bodyfat.

ETA: and carbs hold massive water, which will bloat you and slow you down, so what's your point?

The hydrostatic and Bod Pod uses your weight and measurements with the volume. If you lose water weight, it does NOT show as a decreased body fat%, that is exactly the purpose of those tests. They give you your mass in terms of lean mass, body fat and water.