Excess intake of which nutrient strains the liver and reduces bile production, potentially causing diarrhoea?

• A. Carbohydrates
• B. Vitamins
• C. Fats
• D. Protein

Answer: (D)

Protein metabolism relies heavily on the liver. When protein is consumed in excess, the liver must deaminate amino acids and convert the resulting ammonia into urea for excretion. This increases the liver’s workload. If the liver is busier, its ability to maintain other functions, including bile production, can be temporarily affected. Less bile means poorer fat digestion, so fats aren’t emulsified efficiently, and undigested fat in the gut can pull water into the intestine, contributing to diarrhoea. Carbohydrates and vitamins don’t impose this same nitrogen-processing load, and fats, while they require bile, are less likely to reduce bile production even when eaten in excess. So excess protein best fits the scenario of straining the liver and reducing bile production, with possible diarrhoea as a consequence.