The
WAITING
GAME
Time delay
INTERMITTENT FASTING isn’t as much about limiting food as it is limiting the time spent eating food. Here’s how intermittent fasting (IF) works:
IF is a regimen that cycles between periods of fasting and eating, mimicking the patterns of the hunter-gatherer days of our distant past. The theory is that humans have evolved to accept this sort of eating pattern.
THE
WHAT
Weight loss is often the primary goal. Indeed, researchers reviewing IF trials for a report published by the National Institutes of Health concluded that IF may be a promising way to lose weight and improve metabolic health for those who don’t mind the periods of no eating at all.
THE
WHY
The time you eat depends on the IF regimen. Under the 16:8 regimen, for example, a person typically eats just two daily meals, instead of three, during the 8-hour eating window, with no snacking in the remaining 16 hours. By eliminating a meal each day, they automatically drop their calorie intake.
THE
WHEN
Longer periods of fasting are not necessarily better. Going too long without food might prompt the body to store more fat.
–Johns Hopkins Medicine
Water and zero-calorie beverages such as coffee and tea (served without cream or sugar) are allowed during fasting periods in some IF plans.
THINGS TO
CONSIDER
Level of Abstinence
Some IF plans call for total restriction of calories during the fasting period; others allow for reduced calorie intake during fasting periods.
Weight Loss
With fewer hours available for eating, fewer calories are generally consumed. However, binge eating during non-fasting hours may sabotage weight loss goals.
Calorie Counting
IF plans with the shortest amount of time for eating—say, the 20:4 regimen’s 20 hours of fasting, four hours of eating—may allow you to eat as much as you wish. IF plans generally encourage dieters to pay attention to the quality of the food eaten as much as the timing.
The 24-Hour Version
Fasting for an entire 24-hour period is part of several IF regimens. Fasting for longer than that is discouraged, as it can be counterproductive and even dangerous.
Johns Hopkins Medicine reports these potential benefits of IF.
for your health
Performance. Young men fasting for 16 hours lost fat while maintaining muscle mass.
Memory. Studies showed IF boosts working memory in animals and verbal memory in people.
Heart. IF improved blood pressure, resting heart rate and other cardiovascular measurements.
THREE
FASTING PLANS
24
HR
FAST
CONS
Fasting for 24 hours can be difficult to maintain at the start.
WHOLE-DAY FASTING
There are many fasting regimens with varying levels of difficulty. Here are a few examples.
Also called intermittent calorie restriction, it requires fasting for 24 hours at a time, two to three times a week, with a week separating each fasting cycle.
PROS
Fasting is done on non-consecutive days. Some versions allow snacking (500 calories for women, 600 for men) on fasting days.
1|1
CONS
Fasting and eating periods are split evenly, and there is no “week off” between fasting as there is with whole-day fasting.
A 24-hour fast every other day, without a week separating fasting cycles.
ALTERNATE DAY FASTING
PROS
Some alternate-day fasting regimens allow participants to consume 25% of their normal calorie intake on fasting days.
FAST
EAT
20:4
CONS
The 20:4 version, calling for 20 hours of fasting per day, is the most difficult, as it typically has time for just one meal per day.
The first number refers to sustained hours of fasting per day, the second number is sustained hours of eating. Variations include 12:12 and 16:8.
TIME-RESTRICTED FEEDING
PROS
There are versions with smaller and larger windows of opportunity to eat, so the participant can decide how many hours each day’s fast will last.
FAST
EAT
These convenience foods from Hy-Vee can help you power through.
LOW-CALORIE
SNACKS
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Smartfood Popcorn
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Hy-Vee Cheese Snacks or Sticks
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Halo Top Fruit Pops
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Sliced Peaches
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Diet Snapple
Enjoy calorie-free iced teas in peach, raspberry and half tea/half lemonade flavors.
Brach's Drops
Make fasting hours go faster with sugar-free hard candy in lemon and cinnamon flavors.
dietitian services
Hy-Vee’s nutrition experts can help you meet health and wellness goals.
Find Your Dietitian
Healthy Habits: A 4-week program to help customers develop an eating plan for a balanced lifestyle. The program, which costs $99, includes weekly one-on-one support from a Hy-Vee dietitian to answer questions and track progress. Simple dietitian-inspired recipes, grocery lists and balanced meal plans are also part of the program.
Nutrition Store Tours: Available virtually or in-person, these tours are led by a Hy-Vee dietitian, who focuses on a specific topic such as general wellness, heart health, diabetes, food and fitness, plant-based eating or one of the top nine food allergies.
Intermittent fasting resulted in a 3.2% to 8% weight loss in overweight or obese adults in trials lasting 2 to 6 months.
—National Institutes of Health
pro tip:
is IF a fit?
Intermittent Fasting [IF] isn’t for everyone and may not be recommended for certain population groups such as athletes, anyone with diabetes, or people who are prone to getting ‘hangry.’ For those people, and really for anyone looking to make long-term, sustainable changes, I recommend working with a Hy-Vee dietitian and trying our Healthy Habits program instead of IF.”
—Jena DeMoss, RD, Hy-Vee Dietitian
fasting
caveats
Talk to your doctor before starting an IF regimen. Also seek their advice if you experience anxiety, headaches or nausea after starting IF.
IF is not recommended for children under
18 or for people with a history of eating disorders such as anorexia or bulimia. It is also not recommended for women who are pregnant or breastfeeding.
Stay on track by filling up on these nutrient-dense foods suggested by Hy-Vee dietitian Jena DeMoss: yogurt, fruits, vegetables, hummus, string cheese, whole grains, edamame, trail mix, oatmeal, eggs, protein bars and nut butters.
NCBI.CBI.NLM.NIH.GOV
Intermittent fasting and human metabolic health
Exercise Training and Fasting: Current Insights
MAYOCLINIC.ORG
What is intermittent fasting? Does it have health benefits?
HOPKINSMEDICINE.ORG
Intermittent Fasting: What is it, and how does it work?
VIEW SOURCES
DAY 1
DAY 2
DAY 3
Intermittent fasting is said to offer a number of health benefits, including weight loss, lowered blood pressure and reduced inflammation. But is it right for you?
24
HR
1|1
20:4
FAST
1|1
CONS
Fasting and eating periods are split evenly, and there is no “week off” between fasting as there is with whole-day fasting.
A 24-hour fast every other day, without a week separating fasting cycles.
ALTERNATE DAY FASTING
PROS
Some alternate-day fasting regimens allow participants to consume 25% of their normal calorie intake on fasting days.
20:4
CONS
The 20:4 version, calling for 20 hours of fasting per day, is the most difficult, as it typically has time for just one meal per day.
The first number refers to sustained hours of fasting per day, the second number is sustained hours of eating. Variations include 12:12 and 16:8.
TIME-RESTRICTED FEEDING
PROS
There are versions with smaller and larger windows of opportunity to eat, so the participant can decide how many hours each day’s fast will last.
