Workout Anytime
Doug Maurer
Done properly, intermittent fasting can be very beneficial for improving health and accelerating fat loss. There are many different types of fasts, but the most popular and practical is called intermittent fasting. 
Intermittent fasting – aka time-restricted eating – is when you restrict your daily food intake to a specific window of time – typically six to eight-hours per day. For example, if you skip breakfast and make lunch the first meal of your day, you might restrict your food intake to the hours of Noon and 8:00 p.m. If you are a breakfast lover, your window could be between 8:00 a.m. and 4:00 p.m.
Many people point out that fasting only works because people eat less than they burn while doing intermittent fasting. This is definitely the case, but the entire trick to losing body fat is finding a way to eat less calories than you burn that you can stick with long term.
Intermittent Fasting vs Chronic Calorie Restriction
The more traditional way to lose weight/fat is to restrict your calories throughout the day by making sure you eat fewer total calories but still maintain a more normal eating window of 12 – 14 hours. There is no question that the calorie restriction works when it is followed. This is very challenging for most people – particularly long-term.
There is also no question that many people find it much easier to eat less than they burn by simply restricting their feeding window to 8 hours per day. For many who make this simple change they find they spontaneously eat less calories without it feeling hard and find they can maintain this lifestyle long term. That is the name of the game when it comes to long term weight management and body fat control!
Many studies have shown intermittent fasting to be a highly effective method for losing body fat and keeping it off, and there are other specific benefits to this approach.
Intermittent fasting provides a number of health benefits including:
- Reduced age-related diseases: Fasting reduces the risk of diabetes, cardiovascular disease, and neurodegenerative diseases; improves insulin sensitivity and overall metabolic health; and lowers cancer incidence.
- Metabolic health: Fasting promotes a shift from glucose metabolism to fat burning, improving so-called metabolic flexibility. It also enhances glucose regulation, improves insulin sensitivity, and promotes ketone body production by the liver.
- Neuroprotection and cognitive function: Fasting increases the production of BDNF, a neuroprotective molecule that aids in neuroplasticity, memory, and learning. The benefits of fasting also extend to protection against neuronal dysfunction and neurodegenerative diseases like Alzheimer’s and Parkinson’s disease.
- Cancer prevention and treatment: Fasting makes cancer cells more vulnerable to chemotherapy while protecting healthy cells—enhancing cancer treatment efficacy and reducing side effects. It does this by exploiting cancer cells’ reduced flexibility that results from mutations in growth signaling pathways.
- Hormesis and cellular adaptation: Fasting activates cellular survival pathways that thrive during intermittent, mild stressors like fasting. This enhances our body’s resilience to oxidative damage, metabolic stress, and toxic environmental exposure.
- Renewal and repair: Prolonged fasting triggers autophagy (cellular recycling) and apoptosis, clearing damaged cellular components. There’s also an increase in stem cell activity and a regeneration of immune cells after fasting cycles.
Who Can Benefit from Intermittent Fasting
Intermittent fasting can benefit a wide variety of people including certain athletes. A 2016 study that tracked the effects of intermittent fasting on 34 resistance-trained men found that restricting their eating to an eight-hour window positively affected several health-related biomarkers, while decreasing fat mass and maintaining muscle mass.
For eight weeks, the participants divided their daily calorie intake across three meals eaten at 1 p.m., 4 p.m. and 8 p.m. They fasted the remaining 16 hours of the day and completed three weekly sessions of resistance training on non-consecutive days. Among the biomarkers noted, there was a significant decrease in blood sugar for the intermittent fasting group as compared to the normal diet group.
Potential Pitfalls when Intermittent Fasting
The biggest challenge with intermittent fasting is making sure you get adequate protein. This is particularly important as you age because once you get on the other side of 45 your body has a harder time digesting and absorbing protein so your need for protein actually goes up.
To make sure you do not fall into this trap check out this previous blogpost that provides suggestions on how to make sure you get enough protein into your diet while intermittent fasting.
Contraindications for Fasting
Although most people can safely benefit from intermittent fasting, it’s important to take caution if you have certain health challenges. Do NOT use fasting if any of the following are true:
- You are underweight with a body mass index (BMI) of 18.5 or less
- You are malnourished
- Children should NOT fast! They need nutrients for continued growth; if your child is obese, consider cutting him or her back on refined grains and sugar to promote weight loss
- Pregnant and breastfeeding women should NOT fast because a consistent flow of nutrients must be shared with the baby to ensure its well-being.
- Anyone who has or has experienced an eating disorder including anorexia and bulimia needs to stay away from fasting.
- If you take medications that should be taken with food you will need to be very cautious about fasting and consult with your physician first. This is especially true for diabetics and those with gout.
- You have a medical condition – check with your physician first.
Take Home
Intermittent fasting is not magic and does not work for everyone, but for many it provides a much easier way to keep caloric balance and lose fat!