Liquid-only diets are aggressive weight loss plans appropriate for when you have a lot of weight to lose, and haven't had success using traditional weight loss strategies. For a limited period of time, you get all of your calories in the form of shakes, soups and other liquid-based meals. The very-low calorie content of liquid-only diets causes rapid, sustained weight loss. But don't confuse liquid programs with fad diets. Liquid programs require medical supervision and are clinically supported for treating obesity.
Weight Loss on Liquid-Only Diets
Liquid meal plans provide 800 to 1200 calories per day, on average, which promotes rapid weight loss. These diets can cause a weight loss of 2 to 4 pounds a week, according to a clinical review published in the September 2014 edition of the "Nutrition Bulletin" journal.
The amount and rate you lose depends on a number of factors such as your starting weight, age, gender and individual metabolism. In one study, participants lost an average of 35 pounds over 14 weeks. The participants were mostly female and age 46, on average, according to results the British Journal of General Practice published in February 2013. Another study published in the June 2006 issue of the journal "Obesity Surgery" reported that participants lost 20 pounds in six weeks.
Specially Formulated Meals Promote Weight Loss
Rapid weight loss is possible on a liquid meal replacement program, due to the carefully formulated liquid meals. Each product is low in fat and calories, with enough protein to support your lean muscle mass and moderate carbohydrates to supply energy. For example, a commonly used program offers shakes, soups and other liquid-based meals that contain roughly 160 to 170 calories each, when prepared. The products have 14 grams of protein, 3 to 5 grams of fat and 18 to 21 grams of carbohydrate. Because you can't replicate this nutrient breakdown with store-bought shakes, you must visit a weight loss clinic and enroll in their liquid-only program.
What to Expect on a Liquid-Only Plan
Positive change happens quickly when you follow a liquid-only diet, as directed. Most liquid meal replacement programs are followed in phases. Typically, the first phase is the most aggressive, as it is the phase where you replace all your meals with liquid-only products.
At most clinics, phase one lasts 12 weeks. Expect to attend weekly nutrition education classes while a clinician monitors your health and progress. During phase two, a transition phase that lasts six weeks, you eat one self-prepared meal -- typically dinner -- and continue replacing the rest of your meals with liquids. A key part of most liquid meal plans is the long-term maintenance where your clinic provides access to continued support to help you keep the weight off over time. Keep in mind each clinic may tailor their program slightly differently.
Liquid-Only Diet Risks and Considerations
A weight loss clinician monitors your health during a liquid-only program. Side effects are possible, however, 96 percent of the more than 8,000 participants in
a April 2012 edition of the "International Journal of Obesity" reported no negative side effects. A very small number of participants in that same study experienced gallstones. Rapid weight loss is a risk factor for gallstones, as it causes the liver to release extra cholesterol into bile, where it can crystallize. A clinician will evaluate your health to determine whether you're a candidate for a full-liquid meal replacement plan. Liquid-only diets are not suitable if you are pregnant or breastfeeding, have severe kidney or liver failure, certain heart conditions, or if you are over 65 years of age or under 18.
Keeping It Off After a Liquid-Only Diet
Most liquid-only programs gradually transition you to self-made meals. During the program, you learn how to portion foods and meals properly to prevent overrating once you return to solid foods. You also learn how to make healthy food choices and how to build nutrient-packed meals using whole foods. Without learning these crucial tools to keep the weight off, you risk regaining what you lost and undoing all of the hard work. You'll learn how to make sensible changes and how to have your favorite foods -- such as birthday cake or pizza -- in moderation, as well as how to make healthier versions of those foods.
- British Journal of General Practice: Feasibility and Indicative Results From a 12-month Low-Energy Liquid Diet Treatment and Maintenance Programme for Severe Obesity
- Obesity Surgery: Change in Liver Size and Fat Content After Treatment With Optifast Very Low Calorie Diet
- Mercy Weight Loss and Nutrition Center: OPTIFAST, A Medically Monitored Weight Loss Program
- Nutrition Bulletin: Formula Food-Reducing Diets: A New Evidence-Based Addition to the Weight Management Tool Box
- Chicago Weight Loss Clinic: Chicago Weight Loss Clinic: Optifast - Clinically Proven to Work
- International Journal of Obesity: Multicenter Evaluation of an Interdisciplinary 52-Week Weight Loss Program for Obesity With Regard to Body Weight, Comorbidities and Quality of Life - A Prospective Study
- National Institute of Diabetes and Digestive and Kidney Diseases: Gallstones
- Optifast: Pregnancy, Breastfeeding and Other Health Conditions on the Optifast VLCD Program