No studies, but it's plain to see that ubiquitous calorie labels and databases did nothing to slow the increase of obesity. How did previous generations survive without them?
FWIW I've been maintaining a 30% loss for years and at no point during or since did I attempt to tally CI or CO. If I did, I'd still need to translate the numbers into an addition or subtraction of a whole food so why not just skip that step? As a description CICO is a tautology--there's nothing to discuss. As a prescription for control it just doesn't seem to deliver for the population who need it. Not once have I met an overweight person who doesn't understand calorie deficits.
Lots of: urban hiking, cycling, sprinting
Lots of: fresh meat, seafood, eggs, organs, tubers, starch fruits, vegetables, meat fat, dairy fat, oil fruits
Some: cured meat, dairy protein, sweet fruits, rice, pulses, tree nuts, oil seeds
Minimal: soy, refined proteins, sugar, liquid carbohydrate, grains, refined oils, peanuts