Five Day Fasting Program

For most people, yes. However, if you have a health condition or any concerns about fasting, you should speak to your healthcare provider before starting the RFF fast.

Since the RFF limits calorie intake, common side effects may include fatigue, headaches, dizziness, musculoskeletal pain, nausea, difficulty and concentrating. 

Significant changes in diet can also cause changes in your gut such as cramping, gas, bloating, constipation or diarrhea. Symptoms in most people will be mild and temporary.

RFF is designed to prevent many of these typical fasting side effects by providing specific macro and micronutrients. However, because it is still a low-calorie program, we encourage you to discuss with your healthcare provider whether the practice of fasting or the use of RFF is right for you. To minimize any risks associated with fasting, please follow these recommendations during the 5-day program: 

• Avoid any strenuous exercising or activities that may burn a high level of calories.
• Avoid extreme temperature environments like hot tubs and saunas, or driving long distances under strong sun or heat.
• Since this is a food-based program, please stop using the product if you experience any symptom of an allergic reaction such as a rash, change in voice, swelling, or fever.
• If you feel light-headed or faint, you should eat something or consume your electrolyte drink. If your symptoms do not subside, please contact your physician, or if you feel this is a life-threatening emergency, call 911.

Time Restricted Eating (TRE)  limits meals to a certain window of time or “eating period” per day. By shortening the time spent eating each day, you are likely to eat less and therefore consume fewer calories.

Keep in mind that there’s a difference between cravings and hunger. Cravings are normal while doing RFF and generally pass within a short period of time. To address cravings, keep yourself distracted, and drink sparkling water (unflavored, unsweetened) and/or non-caffeinated, herbal teas. Like cravings, hunger also generally passes quickly, and we strongly recommend against eating “extra” food, which could take your body out of the fasted state. If your hunger is intolerable, as a last resort before breaking your fast, you may have a slice or two of apple, OR 1 stalk of celery, OR 1 small Persian (“baby”) cucumber of 5-6 inches in length per day. If you add more than one of these additions, it will likely stop your body from being in a fasted state.

You may add:

• Up to 1 tablespoon of dried herbs or spices per day to your soups or other foods in the diet to enhance the flavor (preferably unprocessed)
• Up to 1 teaspoon of sea salt (as long as there are no health contraindications)
• Up to 2 slices of lemon per day (squeezed, not eaten), whether you use it in your soups, herbal teas, or water
• Up to 2 pieces of sugar-free gum per day 
• Unlimited herbal teas (unsweetened and caffeine free)
• All types of sparkling water (no sweeteners of any kind)
• Caffeine up to 140mg per day:
• 1 cup (8fl oz) of coffee (no cream or sweetener)
• OR 2 cups (16fl oz) of black or green tea (traditionally steeped), no matcha
• OR 6 cups (48fl oz) of decaf coffee (no cream or sweetener)

While exercise can help use up available blood glucose and move a person into a ketogenic, fasting state, vigorous exercise can also stress the body, so we do not recommend intense exercise during the RFF. While fasting, keep your activity light and do things like walking, yoga, and stretching.

Listen to your body as you ease back into exercise after fasting. If it feels like it’s too much, it probably is. Don’t push yourself too hard and keep the intensity at a manageable level. Remember, your body needs to recover after fasting, so it may take a few days for you to get back to the level you were at before the fast. 

• Common Definition: Abstinence from all or some kinds of food and drink.
• Physiologic Definition: The switch from burning glucose for energy to burning fatty acids and ketones as a main source of fuel.
• Molecular (Cellular) Definition: The state in which nutrient sensing pathways are inactive or down-regulated.

The Revive in Five Fast causes you to enter both a physiologic and molecular fasting state. It doesn’t trigger nutrient sensing pathways, meeting the molecular definition of fasting. It also triggers the switch from burning glucose for energy to burning fatty acids and ketones as the main source of fuel, so it meets the physiologic definition of fasting.

The RFF also stimulates stress resistance. An important part of stress resistance is autophagy, or cellular clean-up, where the cell targets cellular debris such as misfolded proteins and worn-out cellular components for recycling, leaving the cell rejuvenated.