Intermittent Fasting: The Benefits & How It Works

By prioritizing when you eat over what you eat, intermittent fasting seeks to optimize metabolic function and foster health benefits. Hinging on periods of fasting interlaced with eating windows, it draws from the inherent adaptability of human biology—a throwback to our ancestors who faced unpredictable food availability.

What Defines Intermittent Fasting?


Intermittent fasting is an eating pattern focused not on what you eat but rather when you eat. The core idea is to alternate between periods of eating and fasting. The primary aim is to give the body a break from digestion so that it can focus on other vital functions like cellular repair and fat burning. Research supports the idea that by adhering to specific eating and fasting windows, one can achieve weight management and potentially counter various diseases. The approach is distinct because it doesn’t prescribe any particular foods but instead provides a framework within which eating should occur.

Origins and Historical Context

The concept of intermittent fasting isn’t new; it has roots that stretch back to pre-agricultural times. Early humans didn’t have the luxury of eating whenever they wanted. Instead, they had to hunt or gather food, which led to natural periods of fasting. According to long-term research by Johns Hopkins, human bodies are well-equipped to handle long durations without food, thanks to our evolutionary history. The idea is that our ancient ancestors thrived even when food was scarce. They had evolved to perform well under conditions that involved skipping meals or even days without food. It’s worth noting that until a few decades ago, even modern society had its natural fasting periods. Television channels would stop broadcasting, and people went to bed earlier, essentially ending their intake of food for the day.

Risks and Health Concerns


While intermittent fasting can offer benefits, it isn’t suitable for everyone. Pregnant or breastfeeding women, children and teens, and people with type 1 diabetes should not attempt intermittent fasting without consulting a healthcare provider. It is also important to note that some people may experience negative symptoms, such as irritability, headaches, or nausea when they begin intermittent fasting. Furthermore, there is a risk that extended periods without food might prompt the body to store more fat, which would be counterproductive. Research suggests that it can take two to four weeks for the body to adjust to the new eating pattern, so initial discomfort is to be expected. However, if symptoms persist, it’s crucial to consult a healthcare provider.

Plans and Approaches

There is no one-size-fits-all when it comes to intermittent fasting, but several plans have gained prominence. The 16/8 method involves fasting for 16 hours each day and eating all your meals within an 8-hour window. Another popular approach is the 5:2 method. In this plan, you eat normally for five days a week and limit yourself to a 500–600 calorie meal on the other two days. Regardless of the approach you choose, the objective remains the same: to extend the period during which your body burns fat. Mattson notes that the effectiveness of intermittent fasting comes from metabolic switching—the point where your body has used up its glucose reserves and starts burning fat. Each approach has its proponents, but it’s vital to consult a healthcare provider before starting any of them, especially for those with existing health conditions.

The Science Behind It


Intermittent fasting seems to clash with the typical American eating habits, where meals and snacks are consumed all day long. As Mattson explains, people who stick to such eating patterns are unlikely to burn fat. Intermittent fasting enforces periods of fasting, allowing the body to burn through the calories from the last meal and start using fat as an energy source.

Health Advantages

Studies have shown that intermittent fasting offers more than just fat-burning benefits. According to research published in the New England Journal of Medicine, intermittent fasting may contribute to a longer life, a leaner body, and improved mental capabilities. Mattson suggests it could even offer protection against chronic diseases such as type 2 diabetes, heart conditions, and certain cancers.

Key Health Benefits:

  • Cognitive Function: Research shows improved working and verbal memory.
  • Cardiovascular Health: Lowered blood pressure and improved heart rates have been observed.
  • Physical Fitness: Studies indicate fat loss while maintaining muscle mass.
  • Metabolic Health: Research suggests weight loss and improved insulin sensitivity.

Safety Measures

Before embarking on an intermittent fasting regimen, consult a healthcare provider, especially if you belong to any of the following groups:

  • Children and teens under 18
  • Pregnant or breastfeeding women
  • Individuals with type 1 diabetes
  • Those with a history of eating disorders

Alternative Diets to Intermittent Fasting

While intermittent fasting has garnered attention for its potential health benefits, it is certainly not the only dietary strategy available for those interested in weight management or improved well-being. Various alternative approaches exist that cater to individual preferences and needs.

  • DNA Diet Plans: A significant alternative to intermittent fasting is DNA-based diet plans. These are tailored to an individual’s genetic makeup to optimize health outcomes. For example, the NJ Diet utilizes over 40 different genetic factors to create a personalized eating plan for each participant. A particular NJ Diet review highlights the program’s effectiveness in achieving weight loss and overall well-being. This level of customization provides a unique option for those who find intermittent fasting less suited to their needs.
  • Keto Diet: The ketogenic diet focuses on high-fat, low-carbohydrate foods to put the body into a state of ketosis, where it burns fat for energy. This diet has been shown to aid in weight loss and improve certain health markers.
  • Paleo Diet: This diet takes inspiration from the dietary patterns of our hunter-gatherer ancestors, focusing on whole foods like lean meats, fish, fruits, vegetables, nuts, and seeds.
  • Vegan Diet: Excluding all animal products, a vegan diet emphasizes plant-based foods. Not only is it ethically motivated, but it has also been linked to various health benefits, including lower cholesterol and blood pressure levels.
  • Mediterranean Diet: This diet mirrors the eating habits of people living around the Mediterranean Sea, emphasizing fruits, vegetables, fish, olive oil, and moderate wine consumption. It’s known for its beneficial effects on heart health.
  • Low-Carb Diet: As the name suggests, this diet focuses on reducing carbohydrate intake, usually for the purpose of weight loss or blood sugar control.



Intermittent fasting offers an alternative approach to weight management and overall health improvement. However, not everyone can or should engage in intermittent fasting. Consulting a healthcare provider prior to starting any new diet plan is advised. Intermittent fasting is not just a passing fad but a lifestyle change with potentially beneficial outcomes. Remember, the effects of intermittent fasting may vary from person to person. Be vigilant about how your body responds, and consult a healthcare provider if you encounter any adverse symptoms.