We haven't arrived at that age of sci-fi fiction yet when a complete meal can be had in just one pill. But we've come close.

Pre-packaged powdered drinks and ready-to-eat bars that contain a rich array of vitamins and minerals, high amounts of protein, low to moderate servings of carbohydrates and low quantities of fats may not be pills, but they are complete meals in themselves. We call them meal replacement products (MRPs) and their presence has generally made cooking, calorie-counting and weight loss or gain that much easier. Simply tear the wrapper and breakfast is ready in a bar. Mix the powder with water and presto! Lunch is served.

MRPs derive their protein from such sources as whey, casein or albumin; their carbohydrate content is usually taken from maltodextrin, brown rice or oat fiber while their fat content comes from plant-based oils. Because they're portable, readily available and nutritious, MRPs have gained a wide following from fitness enthusiasts. Bodybuilders take advantage of the high-protein content in these MRPs in their quest to build bigger muscles and get ripped bodies. It has also gained following ranks of the regular folks like you and me who use them as meal substitutes in order to lose a few pounds and look decent in a bikini. Even those who are super-busy in their careers have found a friend in that edible bar when lunch gets turned into a work hour to meet the demands of the job.

While so many rely on and ingest MRPs on a regular basis, the nagging question remains: Are MRPs safe?

Without beating 'round the bush, the answer to this question is yes, as long as they're used as directed. MRPs are supposed to contain the nutrients the body needs for good health. An MRP that has around 200- 300 calories, no more than 35 grams of carbohydrates, 15 grams of protein and 8 grams of unsaturated fat; 3-6 grams of fiber, less than 20 mg of cholesterol, no more than 300 mg of sodium and at least 50% of the recommended intake of vitamins and minerals should provide your body with the nutrition it needs for the particular meal it seeks to replace. While they can take the place of a maximum of two meals in a single day, MRPs are not meant to be the sole source of nutrition. Safe intake means taking them in conjunction with a carefully planned diet regimen with lots of fruits and vegetable. Because data is severely lacking on the effects of long-term use or overconsumption of these MRPs, they're usually recommended only for short-term use and in moderation. This is because the impact of a high-protein diet such as what these MRPs are made of on a person's kidneys and liver has not yet been fully established. Besides, the efficacy of relying on them to sustain any weight loss regimen still needs to be determined by long-term scientific research.

Pending results, it's best to take a cautious attitude towards MRPs. For now, if you don't take in too much and use them as directed by your health or fitness professional, then you shouldn't have to worry about anything. Unless, of course, a new study proves otherwise.

Last but not least, be sure to read this Shakeology review, it's my preferred meal replacement product. Also, don't forget to look at this article called "does Shakeology really work".

Author's Bio: 

Kylie is a full-time mother of 3 and a freelance writer for ShakeNutrition.com.