It feels like there is a stone in my stomach and my hunger has all but disappeared. Im 5 weeks in and normally an overeater. When i eat something, the stone-stomach feeling stays. i’m doing lots of aerobic activity and still no change in hunger for the last three days. What dis?
It’s kind of a neutral feeling, not good or bad, not painful or constipation, just sort of feels like my digestion and appetite turned off.
Welcome to fat adaptation
Your hunger signals are turned off
Yeah, you feel full all the time
Try some intermittent fasting and enjoy the ride
Well, even though you may well be 100% fat adapted at this point, enzyme insufficiency is common after years of being a sugar burner.
It can take from several months to many seasons for the body to start making the optimal levels of the new enzymes, depending on what cuisine you eat and whether you’re dousing each meal with iced beverages or mineral water that dilutes or otherwise interferes with enyzmatic capacity.
There’s a big difference between satiety/contentment kinda fullness and a stagnated lack of digestive fire with its heavy & slow stomach/gut.
The ketogenic gut goes through a process of rebalancing enzymes and gut bacteria. It’s part of the overall recomposition process. For more on LCHF/keto gut health see the work of microbiologist Norm Robillard (author of Fast Tract Digestion) and pharmacologist Grace Liu’s “Warrior Gut” presentations.
You can help that along by using spices (frequent sautes of a base of good fat with a little chopped onion + 1-2 tblsp shredded ginger and a chopped green chilli and/or a little garlic - are great for digestion, and an enticing aromatic base for many tasty meals. Also: if you had a little black pepper or red pepper, it multiplies the curcumin potency and delivery many times over).
Supplementing with enzymes is something a lot of people do - though I’m not a fan of it due it not addressing deeper functionality: enzyme production.
In eastern medicine of India, “healthy digestive fire” is the gateway of all health, because of how it makes nutrient absorption possible, along with the elimination of toxins. Personally I’m a devotee of enzyme precursors found in Turmeric and Ginger (cousins in the curcumin family) and several other spices. Around month 2 on keto my stomach also felt heavy and sluggish - and I didn’t have ooomph to digest even one meal a day. So, I started to attend to enzymatic support by making a batch of Ginger/onion/chili sautes and storing it in the fridge to reheat and add to meals - and it made a huge difference. When eating less spicy cheesy dishes, I made a point to have a small glass of red wine to help with the digestion. Soon after that I learned how Ginger lowers cortisol, so decided to officially supplement in measured amounts daily.
And my digestive fire/harmonious gut has been most excellent - whether on a 20-24 hour IF day or on a feast day with 3 meals, etc. 
There is a curcumin metabolic pathway involving a unique enzyme in an intestinal microorganism. Also, enzyme co-factors are really interesting.