In the recent days osmolality of sports drinks, energy drinks, infant formulas and various other beverages food products has become a topic of discussion amongst nutritionist, sports persons and consumers alike.

Studies have shown that hypertonic foods and beverages when consumed can lead to severe discomfort including stomach pain and even vomiting. This happens because hypertonic foods cause water from the intestinal cells and capillaries to be drained into the gastrointestinal tract.

Hypertonic foods have also been shown to reduce the absorption of essential nutrients which can nullify the claims of energy drinks and nutritional shakes. Hypertonic drinks reduce the gastric emptying time and can make the person feel uncomfortable, if he/she is doing an exercise.

It has also been found that slightly hypotonic foods are more rapidly absorbed and are a better way of rehydrating and energising when compared to hypertonic foods. Hypertonic drinks are also easier to consume because of their milder taste and greater feeling of refreshment after consuming them.

The osmolality of the food especially makes a difference when it is consumed as a major source of energy and hydration during or after exercise. These effects are not as marked when the food is consumed at resting state.

Because of these concerns a number of companies have started labelling their products as hypertonic or hypertonic so that the consumer can make the correct choice.

The osmolality of a food after reconstitution can theoretically be calculated by knowing the exact composition. However osmolality is a colligative property and depends on the number of solute particles and not on the concentration of solute. The number of solute particles can vary based on ionisation or complexing of the components with each other, therefore it is very important to experimentally measured the osmolality using an osmometer.

There are two main types of osmometers available-