What Is the ProLon Diet?

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At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition.

The ProLon Fasting-Mimicking Diet is a pre-packaged meal plan developed after 20 years of research conducted at the University of Southern California and funded by the National Institute of Health. The ProLon diet is a 5-day fasting-mimicking diet, sold as a complete meal plan by its creator, Valter Longo, PhD.

Dr. Longo is the Edna M. Jones Professor of Gerontology and Biological Sciences and Director of the Longevity Institute at the University of Southern California –Leonard Davis School of Gerontology, Los Angeles.

Overall, ProLon is a plant-based diet designed to attain fasting-like effects while providing both macronutrients and micronutrients to minimize the burden of fasting. The goal is to enhance your metabolism and make you feel energized and refreshed.

The diet includes vegetable-based soups, energy bars, energy drinks, chip snacks, tea, and a supplement containing minerals, vitamins, and essential fatty acids. While on the diet, people are encouraged to eat only what is supplied for their 5-day fast.

What Experts Say

"Quite simply, the ProLon Diet is a fasting-mimicking diet that mimics fasting for the body while giving your body enough nutrition to sustain [itself]. This diet triggers autophagy in the body, which is the body's way of cleaning out damaged cells that are not useful anymore—kind of like your body's ‘housekeeper’ for your cells."

-Brynna Connor, MD

What Can You Eat?

Because the ProLon Diet is a pre-packaged meal plan, creators indicate that a person following this diet should not eat any food other than that which is given by the meal plan. Overall, the plan includes a variety of soup mixes, oils, olives, kale crackers, herbal teas, l-drinks (mostly water and vegetable glycerin), and l-bars (nut-based bars).

What You Need to Know

This diet is a 5-day meal plan, intended to be followed at most once a month, preferably for 6 months. Each day’s worth of food is specifically designed to provide a range of nutrients, so mixing and matching pieces of each meal are not recommended.

A fasting-mimicking diet, such as the ProLon Diet, is low in calories, sugar, and protein, and high in unsaturated fats. As noted by Dr. Connor, the food engineered for the meal plan tricks the body into thinking it is fasting due to low caloric intake (high fat, low carb), but the foods are nutritional enough to sustain your body.

What to Eat
  • Pre-packaged meals offered by ProLon

What Not to Eat
  • Anything not included in the plan

Pros / Cons

Research has shown that intermittent fasting and calorie restriction can reduce inflammation caused by excessive caloric intake. This means that fasting can reverse the bloating you feel after overeating, which is likely the reason that this diet is often viewed as a cleanse.

The ProLon Diet, like other fasting-mimicking diets, is only meant to be followed for 5 days per month at most. In a study where subjects followed a fasting-mimicking diet for 5 consecutive days each month, for a total of 3 months, subjects experienced a lower body fat percentage and lower blood pressure. The loss of body fat facilitated by intermittent fasting has been linked to helping prevent type 2 diabetes and improve cardiovascular health.

According to Darria Long Gillespie, MD, an ER doctor, and TedX speaker, people who have used ProLon have reported increased energy and fewer food cravings once they completed the fast. They also have reported improved focus and clarity.

"Multiple cycles of ProLon also [potentially] support overall metabolic health," Dr. Gillespie says. “I’m a big proponent of intermittent fasting, as are many of my medical colleagues, but I find it really hard to actually do. I have always admired the research behind ProLon.”

It is further theorized that intermittent fasting, paired with energy restriction, can help prevent cancer, though additional research is needed. Less desirably, fasting and fasting-mimicking diets are known to cause hypoglycemia and dehydration. In this regard, those with diabetes should not fast or follow this diet.

  • No planning involved

  • Food is provided

  • May offer health benefits

  • Short-term commitment

  • Limiting in what you can eat

  • Expensive to use

  • May cause dehydration or hypoglycemia

  • Not a long-term solution

Is the ProLon Diet a Healthy Choice for You?

Fasting and fasting-mimicking diets are known to have some health benefits if followed correctly and done safely. However, in some cases, fasting can cause hypoglycemia and dehydration, among other symptoms.

Fasting-mimicking diets may offer some health benefits, including lower blood pressure and better cardiovascular health. However, diets such as these are dangerous if not followed as intended. Always consult with a healthcare provider before fasting or following any type of diet.

Health Benefits

When it comes to intermittent fasting, people report feeling better overall and having more energy. Here is an overview of some of the potential health benefits of the ProLon Diet.

May Reduce Inflammation

When you overeat or eat certain foods, your body experiences inflammation. This phenomenon partially explains the feeling of being “bloated” after eating too much. The ProLon diet mimics fasting, which is known to reduce inflammation in the body by suppressing pro-inflammatory cytokine expression, decreasing body fat, and decreasing circulating levels of leukocytes.

May Help With Weight Maintenance

Fasting, as well as fasting-mimicking diets, are known to increase metabolism and trigger weight loss. Fasting-mimicking diets, such as ProLon, also are designed to preserve muscle mass by offering nutrients that support the body. According to one study, three cycles of a fasting-mimicking diet resulted in both weight loss and loss of body fat.

May Lower Blood Pressure

While fasting-mimicking diets are known to lower blood pressure, it was actually found that the diet more beneficially affects those who are already at risk for disease. So, while it can lower blood pressure for just about anyone, it is especially beneficial for some.

May Improve Cardiovascular Health

Intermittent fasting, as well as fasting-mimicking diets, are known to cause weight loss, which is linked to better cardiovascular health. Consequently, people who fast are less at risk for heart disease. Even so, it should be noted that losing weight may not be appropriate for everyone.

May Prevent Type 2 Diabetes

Intermittent fasting also is known to help prevent the progression of type 2 diabetes. This benefit is inevitably linked to the weight loss and lowered blood pressure that is experienced by those following the diet.

May Prevent Cancer

Due to the “clean-up” of cells that is triggered by fasting, there is less of a chance for cancer cells to develop. Within this line of thinking, it is theorized that intermittent fasting can help to prevent cancer, however, more research is needed.

Health Risks

If you have or are prone to, any health conditions then you should talk to a healthcare provider before fasting or following a fasting-mimicking diet such as this one. You should especially avoid fasting, or following a fasting-mimicking diet, if you are pregnant, breastfeeding, or extremely active.

Essentially, you should not fast while under any condition where you need more nutritional sustenance than usual. You should also not fast if you are dependent on a steady, consistent diet, such as those who have reactive hypoglycemia or diabetes. Always stop the fast or diet if you experience negative symptoms like extreme thirst and changes in blood sugar.

If you are fasting or following a fasting-mimicking diet, be sure to drink water and take a daily multi-vitamin. Fasting and fasting-mimicking diets may be lacking in some nutrients and are known to cause dehydration, as well as hypoglycemia in those who are prone to it.

A Word From Verywell

This ProLon Diet, as well as fasting in general, is known to provide some health benefits if done safely and correctly. However, it can be dangerous to fast, especially if you have any health conditions or are pregnant or breastfeeding. Talk to a healthcare provider before fasting or following any specific diet.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.

6 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Rangan P, Choi I, Wei M, et al. Fasting-mimicking diet modulates microbiota and promotes intestinal regeneration to reduce inflammatory bowel disease pathologyCell Rep. 2019;26(10):2704-2719.e6. doi:10.1016/j.celrep.2019.02.019

  2. L-Nutra Inc. What is ProLon?

  3. Wei M, Brandhorst S, Shelehchi M, et al. Fasting-mimicking diet and markers/risk factors for aging, diabetes, cancer, and cardiovascular diseaseSci Transl Med. 2017;9(377):eaai8700. doi:10.1126/scitranslmed.aai8700

  4.  Faris “Mo’ez Al-Islam” E., Kacimi S, Al-Kurd RA, et al. Intermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjectsNutrition Research. 2012;32(12):947-955. doi:10.1016/j.nutres.2012.06.021

  5. Aly SM. Role of intermittent fasting on improving health and reducing diseasesInt J Health Sci (Qassim). 2014;8(3):V-VI. doi:10.12816/0023985

  6. Harvie MN, Howell T. Could intermittent energy restriction and intermittent fasting reduce rates of cancer in obese, overweight, and normal-weight subjects? A summary of evidenceAdv Nutr. 2016;7(4):690-705. Published 2016 Jul 15. doi:10.3945/an.115.011767

By Nicole M. LaMarco
Nicole M. LaMarco has 19 years of experience freelance writing for various publications. She researches and reads the latest peer-reviewed scientific studies and interviews subject matter experts. Her goal is to present that data to readers in an interesting and easy-to-understand way so they can make informed decisions about their health.