The buying guide
Protein powder vs meal replacement: compare the whole product
Do not assume a protein powder supplies everything you need from a meal. Compare its full nutrition panel and intended use with the specific meal-replacement product you are considering.
Name the job of the product
Are you adding something to breakfast, preparing a snack, or following a clinician's plan for a complete nutrition drink? Write that purpose down before comparing packages. Similar marketing and similar protein numbers can describe very different products.
Record calories, protein, carbohydrate, fat, fiber, and added nutrients where available. Include the liquid or food used in preparation when evaluating the finished drink. The powder-only panel may not describe the drink you actually consume.
Check the directions and your needs
Follow the preparation instructions for the exact product. If a clinician has recommended a particular nutrition product, do not swap in a generic powder based on protein grams alone. Ask what nutrients and preparation characteristics need to be preserved.
For ordinary shopping, compare the complete offer: package size, shelf life, preparation effort, and cost. Supplements cannot take the place of dietary variety, and a price-per-protein calculation is not a measure of meal completeness.