Food fuels your body, but achieving the right balance of calories and nutrients can be challenging. Intermittent fasting is a popular eating approach, but is it a smart strategy or just a passing trend?
How does it work, and should you try it? Let’s explore the pros, cons, and essential facts about intermittent fasting before you begin.
What is intermittent fasting?
Fasting involves going without eating for a specific period. Intermittent fasting is a plan where you alternate between periods of eating and not eating.
The duration varies. “In the scientific world, you need to fast for at least 12 hours,” Hyer says. Time-restricted eating plans are more manageable; you eat daily but only during designated windows. For instance, you might eat between 10 a.m. and 6 p.m., fasting for the remaining 16 hours. Some people opt for 6-hour, 10-hour, or 12-hour eating windows.
More intense plans follow the 5:2 approach: you eat normally for five days and severely restrict calories (by at least 75%) for the other two days. For example, if you usually consume 2,000 calories a day, you’d limit yourself to 500 calories on fasting days. This extreme approach isn’t for everyone, so consult a healthcare provider before starting any low-calorie meal plans.
Intermittent fasting: Pros and cons
Fasting can aid weight loss and improve some health markers, but it’s not suitable for everyone. Consider these pros and cons if you’re thinking about trying it.
Pros: Intermittent fasting benefits
Intermittent fasting is straightforward. “You don’t need to track meals or count calories. It can easily fit into your life,” Hyer notes.
Research indicates fasting can be beneficial. Studies, mainly on animals and some on humans, show various potential health benefits, including:
- Weight loss
- Lower cholesterol
- Lower blood pressure
- Improved blood sugar levels
- Reduced inflammation
- Enhanced brain health
- Fewer age-related diseases
- Increased lifespan
Cons: Intermittent fasting cautions and concerns
While promising, intermittent fasting isn’t for everyone. Most research has been on animals, and early human studies primarily examined the more extreme 5:2 diet. Researchers are still investigating the benefits of restricting eating to 8 or 12 hours a day.
“The key takeaway for people doing intermittent fasting is: don’t panic,” says Dr. O’Donoghue. “This study isn’t definitive and doesn’t establish cause and effect. However, it raises questions about intermittent fasting’s safety.”
“There are intriguing studies suggesting intermittent fasting may improve blood pressure, cholesterol, and lead to weight loss. But ultimately, it seems more about what you eat than when you eat.”
Fasting may not be advisable for certain groups or those with specific health conditions. Hyer advises against fasting, or consulting a doctor first, if you:
- Are over 65
- Are still growing (children, teens, and young adults)
- Have diabetes
- Have heart, kidney, or liver disease
- Have a history of eating disorders
- Are pregnant or breastfeeding
- Have low blood pressure
- Take medications like blood thinners, diuretics, blood pressure meds, or those affecting blood sugar.