Both contain stimulating alkaloids, theobromine and caffeine, and fat is a notable constituent of cocoa.
"The Home of the Blizzard" by Douglas Mawson
The active principle of tea is called theine; that of coffee, caffeine, and of cocoa, theobromine.
"A Practical Physiology" by Albert F. Blaisdell
Caffeine, it will be remembered, is the methyl ester of theobromine, and can be prepared from it.
"Scientific American Supplement, No. 415, December 15, 1883" by Various
They also contain a crystalline principle analogous to caffeine, called theobromine.
"The Commercial Products of the Vegetable Kingdom" by P. L. Simmonds
This first term gives rise to a series of bodies in lateral groups, of which the most interesting are caffeine and theobromine.
"The Healthy Life, Vol. V, Nos. 24-28" by Various
This bean is rich in protein, fat, carbohydrate, mineral matter, and a stimulant called theobromine.
"Ontario Teachers' Manuals: Household Science in Rural Schools" by Ministry of Education Ontario
Theine, caffeine, and theobromine, all stimulant drugs, are present in tea, coffee, and cocoa, respectively.
"No Animal Food" by Rupert H. Wheldon
Tea and coffee both contain the alkaloid caffeine, whilst cocoa contains theobromine.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 6" by Various