I have also had similar symptoms on a couple of occasions and it is normally after a long period without B12 and then a going back on it too quickly
Kagan, V
Insomnia can be linked to stress, pain, shift work, caffeine, untreated sleep apnea, restless legs, depression, anxiety, medication effects, or withdrawal
Summary: Yes, a calorie deficit consuming less energy than the body expends is the essential mechanism behind all clinically meaningful weight loss, regardless of the dietary approach used to achieve it
By activating GLP-1, GIP, and glucagon receptors, it could increase overall calorie burning, improve how sugars and fats are processed after meals, support steadier blood glucose levels, and gradually reduce fat mass