I think it's possible to alter your metabolism to use more calories and still maintain weight, if you do it in a controlled manner (and increase activity as well).
I think you are probably right, but what would you be trying to achieve in doing so?
"Starvation mode" is what happens when your body is breaking down organ tissue and muscle for energy.
Well it depends on how you define the phrase "starvation mode." I regularly hear people assert that their weight loss efforts (and other peoples') have stalled or plateaued because of "starvation mode." From the context, it seems that they are referring to the "running cool" which I have described and not something extreme like breaking down organ and muscle for energy.
I think you are probably right, but what would you be trying to achieve in doing so?
The more food you eat, the more micronutrients you take in. If you have a higher metabolism, you'll get more micronutrients and still maintain weight. Plus, you get to eat more ice cream. If you previously damaged your metabolism (and I'd call a 1200cal maintenance 'damaged'), then raising your metabolism will be good for you.
Well it depends on how you define the phrase "starvation mode."
I mean, if you're using it wrong, sure. "Starvation mode"...
Eliezer and I have put together this first pass at a recipe for DIY ketogenic soylent--or, as he prefers to call it,The Mildly Surprising Super Ketonic Dietary Replacement Weight-Loss Fluid - It's Not Food, It's Dietary Replacement Fluid!(R) (I am not in full support of this particular preference...)
So let's play Make a Prediction. It seems more likely to be useful than "free associate with why soylent/ketosis is awesome/stupid". Imagine that Eliezer has around a week's worth of infinite willpower (that can only be spent on resisting food cravings etc.). Further, imagine your crystal ball shows you that a month from now, he hasn't lost any weight. What does it tell you about why?
Ketogenic Soylent v1
1 scoop Gold Standard whey protein
1½ tsp calcium citrate powder
1 tsp creatine
½ cup+1 tbsp ground flax
4 tbsp Hershey’s Special Dark cocoa powder
2 tbsp lecithin
⅗ tsp potassium citrate on day 1, increase gradually to 1tsp by day 5, don’t exceed 2tsp
½ tsp iodized salt
⅛ packet Emergen-C
⅕ cup olive oil
1¼ tbsp flaxseed oil
⅗ cup MCT oil
Sucralose to taste
We might need to add water to get the consistency right.
Pills
1 capsule vitamin D supplement/day
2 Opti-Women vitamins per day
1 capsule MSM
Totals Per Day
Calories: 1866
Fats: 193.5g
Carbs: 12g
Protein: 54g
Fiber: 25g
Biotin 250mcg
Calcium 150mg
Chromium 120mcg
Copper 2mg
Folic Acid 600mcg
Iodine 200mcg
Iron 18mg
Magnesium 75mg
Manganese 5mg
Methyl-Sulfonyl-Methane 1000mg
Molybdenum 70mcg
Niacin 20mg
Pantothenic Acid 20mg
Potassium: 5g
Riboflavin 20mg
Selenium 70mcg
Sodium 3g
Thiamin 20mg
Vitamin A 5,000IU
Vitamin B6 20mg
Vitamin B12 100mcg
Vitamin C 250mg
Vitamin D 1600IU
Vitamin E 100IU
Vitamin K 80mcg
Zinc 15mg