(Nescafe®, Nestlé, Switzerland) dissolved in 150 ml hot water. The
CAFFEINE treatment was created by adding 200 mg caffeine (Sigma Aldrich)
to the PLACEBO coffee. The “energy drink” contained 10 ml pure
lemon juice (from a local supermarket) in 150 ml water and either
2.25 g artificial sweetener (sucralose, Splenda®, McNeil Nutritionals
Ltd., USA) for the PLACEBO version, or 25 g glucose (Sigma Aldrich)
for the GLUCOSE condition. Importantly, the main ingredient of the
artificial sweetener used to design the placebo, sucralose, does not
influence glucose homeostasis [35,36]. In a pilot study (n = 5), the
two variants of coffee and energy drinks were matched for their
sweetness.