Liquid Meal Replacements

April 4, 2006
The line has blurred between functional beverages and meals in a can, but both have come a long way toward providing more whole - and wholesome - nutrition.

Fortification technologies have made it quite convenient to get the vitamins and other nutrients we get otherwise from fruits, vegetables and a balanced meal in an easily available format - liquid meal replacements (LMR).

"Counterintuitively, rather than older consumers, young adults with less cemented purchasing and consumption patterns are embracing the new healthy drinks," says Jessica Sadler, market analyst at London-based Business Insights Ltd. The desire to stay healthy, feel good and be energized, according to Sadler, is driving the growing preference of well-being beverage products and LMRs over traditional meals. Formulators need to focus on the details of what makes or breaks the promise of LMRs.

There is no standard definition for LMRs. They can be any beverage substituted for a meal and possessing a similar nutrient profile. Typically sweet and designed to be consumed on the run, they can be a diet shake, a yogurt smoothie, an enhanced milk product or a formulated meal replacement in a bottle or can.

Hospital foods were the first LMRs, formulated to conveniently nourish ailing patients physically unable to consume sufficient solid meals. Initially fortified with nutrients that promoted recovery, LMRs entered the mainstream first through marketing, then because of their health aura and remarkable convenience - even to those not convalescing. Expectant and nursing mothers were early adopters, seeking extra nourishment during and after pregnancy.

Soon, companies extended the logic toward women wishing to lose weight. Marketing to athletes who wished to excel followed, and the category finally broadened to appeal to individuals too busy to eat proper meals.

The most common LMRs are shakes or smoothies, about 10-12 oz., and range from about 180 to 250 calories, of which anywhere from 25 up to 100 are derived from fat. They provide around 25 percent (on a 2,000 calorie-diet basis) of vitamins A, C, D, E, B6, B12, K and the minerals iron and calcium.

Satisfaction Not Guaranteed

Liquid meal replacements are made up at least 25g of carbohydrates, often half or more from sugar. Few contain more than 2g of dietary fiber and typically run anywhere from 5 to 12 percent fat. They range between 6 and 25 percent protein. Their most popular use is as a weight management tool, although their effectiveness has stirred controversy.

Can do? LMRs such as Kashi's GoLean shakes are typically used by dieters, but some studies question their effectiveness.

Studies show LMRs help people lose weight only when used to replace foods and beverages that are nutritionally empty. Liquid calories have the potential to sabotage weight loss because fluids are rapidly digested and provide little sense of fullness. The body does not respond as much to calories as it does to fullness when it comes to eating.

"Our hunger mechanism was designed to ensure that we ate when we had access to food, and that we ate as much of it as we could," says Richard Mattes, Ph.D., food and nutrition professor at Purdue University, West Lafayette, Ind. "Throughout most of human evolution, our next meal was an unsure matter. The strategy, which worked well during leaner times, is becoming a huge problem for every one of us in our current environment laden with food that's tempting, plentiful and energy-rich."

Research at Pennsylvania State University by Barbara Rolls, Ph.D., showed people are satisfied by a certain volume of food, not calories. For manufacturers, this means creating foods with relatively few calories by weight.

Making the Cut

Nutrition plays a very important role in weight loss and weight management. The right foods help one maintain energy levels for the day's physical activity and give the body what it needs to repair and build cells as part of daily upkeep. The irony is that at a time when people are trying to lose weight, optimum nutrition is as important as satiety - both the cutting down of calories and the increased physical activity can render one hungrier and make eating properly a challenge.

One of the key nutritional considerations for anyone trying to lose weight is simply to cut caloric intake. According to Mattes, many factors conspire to make it difficult to reduce one's caloric intake. When we cut our food intake, our bodies switch to a more efficient metabolism and require fewer calories to maintain weight.

Proponents counter that nutritional differences among LMRs are less important than the difference between an LMR and the alternative - a 700-calorie Starbucks cappuccino, a coffee and a donut or fat- and cholesterol-laden fast food breakfasts.

With one out of every three Americans obese and 20 to 40 million on a diet on any given day, the opportunity for better and more appealing liquid nutritional products that help satiety and weight loss is enormous. We're already spending an estimated $1 billion annually on either medically sponsored liquid diets or over-the-counter liquid diet products.

Liquid Values

More than just concentrated calories, LMRs offer value in terms of convenience, nourishment and taste. While the convenience/nutrition combination of liquid meal replacements is a key ingredient for success, manufacturers who add nutritionally responsible formulation will command consumer trust and even more loyalty in the future.

The opportunity is for food formulators to create products that quickly satiate and which leave one feeling satisfied for longer intervals of time. It's important formulators take advantage of breakthrough discoveries in the science of satiety - the science that seeks to understand all of the factors leading to appetite control, a sense of fullness and satisfaction after eating.

LMRs are most effective when they contain 30 percent protein and 60-70 percent carbohydrates, at least 50 percent of which is a combination of viscous and insoluble dietary fiber According to Arun Kilara, president of Kilara Worldwide Inc., Northbrook, Ill. "Volume results in satiety. Dietary fibers and protein add to the feeling of satiety and delay the onset of hunger," says Kilara.

To this end, some new, smarter designs in LMRs are entering the market. Kellogg's Kashi unit makes GoLean ready-to-drink shakes with high levels of protein (15-30g) to help increase satiety, plus extra fiber (7g) for a feeling of fullness. The shakes are rich and creamy to ensure taste is a key consideration for consumers to reach for them, and the assumption is that measurable results keep buyers returning.

Pacific Health Laboratories, Matawan, N.J., designed Satietrol, a potato starch-based, make-it-yourself powder for an LMR. Satietrol claims to work by activating the body's natural appetite-control protein, called cholecystokinin. This protein signals one to stop eating when full and slows the movement of food from the stomach to prolong a feeling of satisfaction. The beverage, meant to be consumed 15 minutes before eating a meal, contains only 80 calories.

LMRs can play a nutritional role in a healthy adult's diet or as a dietary aid for a structured and complete weight loss program. But they should be viewed as a substitute for the occasional meal, not as a permanent replacement. Enjoyed within this context, they can be a useful - and enjoyable - nutritional asset.