Because I’m a dietitian, I often get the question, “What is the best diet for weight loss?” And recently, I’ve been getting a lot of questions related to intermittent fasting. The truth is, there isn’t one answer that works for everyone. Any eating plan that includes fewer calories that your body needs for energy will result in weight loss. As a dietitian, my job is to help each client decide which of those styles of eating fits best within her lifestyle, and then make it as easy as possible for my client to stick with that plan long-term.
If you were to search the internet for diets, you’d likely come up with thousands of results (some of them much, much better than others for overall health).
One of the more popular diets in recent years is intermittent fasting.
Intermittent fasting is the practice of cycling between periods of eating and restricting calorie intake for set periods of time. There are several different ways to implement it, but
The three most popular are:
- The 5:2 Diet, which restricts calories to 500-600 per day for two, nonconsecutive days each week. Calorie intake is normal for the remaining 5 days of the week.
- Alternate day fasting, which restricts calorie intake to about 25% of estimated needs every other day. On other days, calorie intake of up to 125% of estimated needs is permitted.
- The 16/8 method, also called, “time restricted eating” limits the window of eating to 8 (or sometimes 10) hours per day.
If this approach seems crazy to you, please know that it’s not for everyone. But it can be very effective for weight loss and is thought to have several additional health benefits. In fact, some of the dietitians at MNT have even used it themselves! Hey, we’d never suggest anything to our clients that we haven’t tried ourselves! Read on for more info about intermittent fasting, including how to know if it’s right for you.
Is Intermittent Fasting Worth Trying?
Recent studies have shown intermittent fasting to be an effective weight loss strategy. In one small study of obese men, a 5:2 fasting protocol resulted in an average weight loss of 5.3 kilograms (about 12 pounds) over 6 months.
Importantly, though, this and other studies have found it to be no more effective than standard lower calorie diets for weight loss. It works by restricting calories, not by some diet sorcery. That said, some promising evidence suggests that intermittent fasting may have additional health benefits.
Intermittent Fasting Additional Health Benefits:
- Cardiovascular risk: Studies have shown intermittent fasting to reduce certain risk factors for heart disease. A study released just last week found that a 5:2 fasting protocol clears fats from the blood more rapidly than a regular calorie restriction diet.
- Brain health: Neuroscientists have found that 5:2 or 16/8 fasting may improve mood and memory and lower risk for Parkinson’s and Alzheimer’s diseases.
- Inflammation: Intermittent fasting may lower systemic inflammation. In one study of Muslim volunteers, researchers measured blood levels of certain inflammatory chemicals—including Interleukin-6, c-reactive protein, and homocysteine—before, during, and after Ramadan (during which participants fast for approximately 12 hours per day). Levels were significantly lower for both men and women during Ramadan compared to before. Subsequent studies have shown similar findings.
So should you give it a try? It depends on whether or not you can stick with it, long-term. Personality type and lifestyle are key factors that should be considered.
If you read our recent post about Gretchen Rubin’s Four Tendencies, you may recall our argument that weight loss strategies can be matched to personality types. Intermittent fasting is not a great approach for rebels, given their dislike for structure and diet rules.
And certainly, lifestyle plays a role. Many followers of 16/8 intermittent fasting find it easier to fast from dinner to mid-morning. This may prove difficult for those who keep irregular hours, such as shift workers. This is not to say that those with unconventional schedules can’t try fasting; rather, they may be more successful following 5:2 fasting or another approach. And as with any weight loss strategy, consistency is key. For example, those who have social engagements that frequently fall within the fasting window may struggle to stay on track.
Tips for Getting Started with Intermittent Fasting
Does the idea still sound appealing? Here are a couple of tips to get you started:
1. Be mindful of your behaviors and feelings.
Pay particular attention to whether you feel deprived during a planned fasting window, or whether you are tempted to binge eat during or after. If this is the case, you may have trouble over time.
2. Ease Into It
It may be easier to ease into the practice of fasting. If, for example, you want to try 16/8 fasting, you could begin by fasting for only 12 hours per day and gradually lengthen the fasting window. Similarly, if you want to try a 5:2 plan, start by gradually decreasing your calories for just one day per week until you reach the desired level. Ease into a second day from there.
3. Diet Quality Still Matters
Your food intake should be well-balanced, especially on your lower calorie days. While one of the appeals of intermittent fasting is that it doesn’t restrict food choices, your feeding windows shouldn’t be free-for-alls.
And, as always, please contact us if you want help with this or any other weight loss strategy! Our team of dietitians can help you to determine if this is the right plan for you, and how to make it fit into your lifestyle if it’s a good match.