Nimbu pani / shikanji (2 tsp sugar)

One serving of Nimbu pani / shikanji (2 tsp sugar) — 1 glass (250 ml) — comes to 41 kcal, 0.2 g protein, 10 g carbs and 0 g fat. Scaled to 100 g it works out to 16 kcal and 0.1 g protein, which makes it not a meaningful protein source on its own for a beverage item. That single serving is about 2.7% of a 1,500 kcal day and 2.1% of a 2,000 kcal day, so it's more of a filler than a target-hitter on protein without much extra planning.

Walking off Nimbu pani / shikanji (2 tsp sugar) takes roughly 1,025 steps, using the rough approximation of 0.04 kcal burned per step (a population-average estimate for a moderate walking pace, not a personalised number). At ₹5 a serving it costs about ₹500 for every 20 g of protein it delivers, which is a mid-to-high price for protein compared with dal, eggs or soya chunks. It fits nearly every Indian diet type, including vegetarian, Jain, vegan. It works at lunch and the evening snack slot. It's commonly eaten on fasting days (Navratri/Ekadashi-style).

If you want variety without changing the macros much, the closest swaps in the beverage category are Black coffee (no sugar), Tender coconut water, Cold drink (cola/soda, regular), Diet / zero-sugar cola — each keeps a similar role on the plate while shifting the exact protein-to-carb balance a little.