Take breakfast cereals for instance: in larger stores, there are often two dozen or more options, each claiming to be better for your body than all the rest!

Of course, the bottom line is that people want to eat the healthiest foods. But how can one cut through all the marketing fluff to make a quick, nutritious purchase?

Enter Dr David L Katz, director of the Yale-Griffin Prevention Research Centre in Connecticut, USA. Katz, as head of an all-star line-up of medical specialists and researchers, has unveiled a food rating system called the Overall Nutritional Quality Index, or ONQI for short (It is likely to be marketed under the name NuVal). His system evaluates all foods in a grocery store on a 1-to-100 scale, with 100 being the healthiest and 1 being the least healthy.

At the top of the list -- vindicating mothers the globe over -- are fresh veggies and fruits: mustard greens (sarson ka saag) score a perfect 100, as do fresh strawberries, green beans, pineapple, radish, raw spinach, raw broccoli and oranges.Other high scores are squash (96), apples (96), green cabbage (96), tomato (96), watermelon (94), mango (93), bananas (91), plain oatmeal (88) and atlantic salmon (87). On the other end of the spectrum are candies like taffy and popsicles, each scoring a pitiful 1. Other poor performers are hot dogs (5), salami (7), white bread (9), pepperoni (9), diet soda (15) and fried egg (18). An interesting point for Indians is the considerable difference between white rice (57) and brown rice (82).

Before generating a score, the algorithm takes into account the following factors: fiber, folate, vitamins A, C, D, E, B12, B6, potassium, calcium, zinc, omega 3 fatty acids, bioflavanoids, carotenoids, magnesium, iron, saturated fat, trans fat, sodium, sugar, cholesterol, fat quality, protein quality, energy density and glycemic load.

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Katz, who aspires to have the rating used in supermarkets, restaurants, food packaging and other avenues, says ONQI "rates foods based on their overall quality and the more wholesome, more natural foods come out on top."

The immediate fun with ONQI is that it allows you to easily evaluate different types of foods. So, you can put bacon to the test against dark chocolate, or finally compare apples to oranges. But its lasting contribution may be the ability to judge similar foods. For example, next time you have 20 different loaves of bread staring you in the face, wouldn't it be nice to find the highest number and be done with it?

Of course, there are some clear methodological flaws with Katz's system, particularly when put into the Indian context. Most clearly: we don't eat foods individually, we eat meals. While it's nice to know the rating for the boneless chicken breast (39) that goes into our methi murgh, how about the dish as a whole? Isn't it a pain to look up the rating for each individual ingredient? And can you imagine the local subzi wallah dutifully reporting the ONQI scores of his various wares? Not likely.

So, while the system is interesting and promising, it's not without its limitations. Perhaps a variation can be invented that takes evaluation to the next logical step: rating recipes based on the ingredients and recommended portion size.

As it stands, however, the system will be introduced this September in a select number of US grocery stores. The ONQI rating will be found on pricetags, so that consumers can weigh both monetary cost and nutritional value when making a purchase. No plans have been announced to introduce the system in stores world wide.

Check out a list of various foods and their rankings! 

Photograph: Sam Panthaky/AFP/Getty Images