What to Know About Intermittent Fasting - Including Meal Plans

In this article:

• Intermittent fasting can be effective for improving health and losing weight, but it has risks and side effects too.
• Some IF patterns include 16:8, alternate-day fasting, and 5:2 fasting. Each pattern has benefits and challenges.
• If you choose to follow an intermittent fasting routine, be sure to select nutritious foods and stay hydrated.
• Talk to your healthcare provider if you’re considering intermittent fasting or starting a new diet pattern.
• Lark can help you manage weight with or without GLP-1s as you log food, get tips for eating healthier, and make small changes that can turn into healthy habits.

Intermittent fasting, or IF, is a popular trend. It involves periods of eating followed by periods of fasting or eating far less than your body’s needs. Some evidence suggests that it may be effective for weight loss and have some metabolic benefits, but there’s a lot that’s still unknown. Here’s what to know about intermittent fasting, its effects on the body, and how to get started if you’re interested. Be sure to talk to your healthcare provider before starting any new diet plan, especially an extreme one like IF.

Possible Effects on Health and Weight Loss

Some research finds positive effects on health and weight loss, but there’s still a lot that’s unknown.

Health Effects

According to a review article on intermittent fasting published in the journal, Nutrients, intermittent fasting may have some health benefits. For example, inflammation in your body may go down within a few hours of starting a fast. Inflammation is linked to the development of chronic conditions like heart disease, diabetes, certain types of cancer, and more.

Here are other possible health effects of IF.

• Reduced blood pressure
• Improved lipid profile, such as lower levels of unhealthy LDL-cholesterol
• Increased insulin sensitivity or better blood sugar regulation

These effects are not guaranteed, and it’s important to talk to your healthcare provider before starting an IF program.

Weight Loss

Mayo Clinic states that intermittent fasting can help with weight loss by reducing calorie consumption. Alternate-day, 16:8, and 5:2 IF routines are all designed to limit the duration of time during which you can consume your calories. This can help keep total calorie consumption down.

There is also some evidence that intermittent fasting has effects similar to those of a ketogenic, or very low-carbohydrate diet. In a 16-hour fasting period or during the “fasting” days of 5:2 or alternate-day patterns, your body may enter ketosis. That means your body is using mostly fat and very few carbohydrates as fuel for energy.

Risks and Precautions

Intermittent fasting can lead to side effects.

Here are some common ones.

• Extreme hunger
• Fatigue and lethargy
• Nausea
• Constipation
• Headaches
• Trouble concentrating
• Irritability
• Difficulty sleeping

Side effects may decrease over time, but it’s best to check with your healthcare provider if you experience any. Women who are pregnant, people with a history of eating disorders, individuals with diabetes or who are on blood sugar medications are among the patients for whom IF may not be safe.

Another concern with IF is that if you feel too tired or achy, you may not want to exercise. Staying active is important for weight management and has physical and mental benefits.

Sample Intermittent Fasting Schedules

There are different types of patterns that you can follow for intermittent fasting. If you’re considering IF, talk to your healthcare provider and consider individual factors like personal preferences and schedules as you decide which to follow.

16:8 Pattern

With a time-restricted or 16:8 pattern, you may fast for 16 hours and have an 8-hour eating period. For example, you might fast from 6:00 p.m. to 10:00 a.m. You then consume all of your calories for the day between 10:00 a.m. and 6:00 p.m.

This schedule can allow people to fit their IF plan into their daily lives. For example, if you have a special event like a luncheon at work or dinner with friends, you can plan your schedule, so that the special event falls within your 8-hour eating window.

Alternate-Day Pattern

With an alternate-day pattern, you might have a very low-calorie consumption on your “fasting” days, with a higher consumption on your “eating” days. For example, you might consume 25% of your calorie needs on fasting days and have 125% of your calorie needs on eating days.

This averages out to 75% of your calorie needs, which would mean that it would lead to weight loss. If you need 2,000 calories a day to maintain your weight, you'd consume 500 calories on fasting days, and 2,500 calories on eating days.

This pattern can allow for larger meals and special occasions. However, it can be difficult to fit into a typical schedule. For example, it doesn’t allow for consecutive high-calorie days, so it could create challenges if you want to have special meals on both weekend days.

5:2 Pattern

With a 5:2 pattern, you would have 5 days of “normal” eating, followed by 2 days of “fasting.”

On “normal” eating days, you consume the number of calories you need to maintain your weight. On the 2 “fasting” days, you consume about 500-600 calories each day.

This pattern can be relatively easy to fit into a typical schedule. You can also plan ahead to make sure that any upcoming special events fall during your 5-day period of normal eating.

What to Eat on Your Intermittent Fasting Plan

There’s a lot of variability with food choices while following an intermittent fasting plan. Here are some common guidelines.

What to Eat While “Fasting”

If you’re following a 16:8 pattern, you’ll have a 16-hour fasting period each day. During that time, it’s important to stay hydrated. Water, coffee, tea, and calorie-free beverages are allowed. Avoid adding calories from sugar, cream, flavoring syrup, and milk when you drink beverages.

If you’re following an alternate-day eating pattern or a 5:2 pattern, you’ll be consuming some calories on your “fasting” days. You might have about 500 calories. Vegetables, lean proteins, and fruit are low in calories and may be good choices.

Here are some examples of what a 500-calorie day can look like.
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Be sure to drink plenty of fluids and to ask your healthcare provider for approval before starting your plan.

What to Eat During Eating Periods and Days

When you’re eating, you’re either eating “normally,” such as on a 16:8 or 5:2 plan, or you’re having slightly more than normal, such as on an alternate-day IF plan. In other words, your “eating periods” aren’t a time to overeat dramatically. Sticking to nutritious foods and using portion control can help you achieve your weight and health goals.

Here are additional tips for smart eating during your eating periods while doing IF.

• Assess your hunger before you eat. It’s best to only eat when you’re hungry
• Try to maintain a consistent eating schedule
• Stay hydrated
• Don’t rely on calorie-dense, low-nutrient foods
• Eat mindfully
• Eat separate meals and/or snacks rather than grazing constantly

How Lark Can Help

Intermittent fasting can be effective for weight management, but it’s easier when you have the support you need. Talk to a healthcare provider to determine the best weight management and healthy eating plan for you. Lark offers additional tools and support. Your Lark coach is available 24/7 for nutrition and physical activity coaching and tracking. Lark can help you make healthy choices and establish habits that fit into your lifestyle, so you can lose weight and keep it off with or without GLP-1 medications.

Click here to see if you may be eligible to join Lark today!

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