Intermittent Fasting for Weight Loss

It’s hard to lose weight.

Although fasting (going 24 hours or more without eating) is an excellent way to lose weight, it can be hard. Perhaps this is why I see a growing number of patients experimenting with intermittent fasting.

Intermittent fasting, also called time restricted eating, is a manner of eating in which all the daily calories are eaten in shortened period of time. The most common way that people do this is through a 16:8 pattern in which all food is eaten over an 8 hour window, and the body is allowed to “fast” for 16 hours.

But there are some problems with this strategy.

While healthy, intermittent fasting doesn’t usually lead to weight loss. This is typically because people end up eating the same amount of calories, only over a smaller period of time.

That’s not all. Emerging research suggests that patients with heart disease may be putting themselves at risk by following 12-16 hour intermittent fasting diet.

“A study of over 20,000 adults found that those who followed an 8-hour time-restricted eating schedule, a type of intermittent fasting, had a 91% higher risk of death from cardiovascular disease.”

The good news is that there are alternatives to the intermittent fasting that are safer and work better!

The 5:2 Diet

One alternative to intermittent fasting is a 5:2 Diet, where you eat a regular diet five days a week, but drop your caloric intake to 25%. If you eat 2000 calories normally, you would aim for about 500 calories two days of the week.

Although a 5:2 approach is more effective for weight loss than a regular low calorie diet, it can still be challenging. Because I am always looking for ways to make things easier for my patients, I was so excited to read the results of a study that combined a 5:2 schedule with a nutritional formula very similar to what I use in clinical practice. The benefit of using a nutritional formula is that participants were able accurately lower their caloric intake on their fasting days without having to count calories or make special meals.

In the study, the researchers had patients substitute their meals two days a week with a nutritional formula. They ate their regular diet the remaining five weeks. The study went on for 16 weeks. Compared to two control groups the 5:2 nutritional formula group:

  • Lost weight (21 pounds!)

  • Lowered blood sugar

  • Lowered fasting insulin levels

  • Lowered markers of inflammation

  • Reduced hip and waist circumference

  • Lowered blood systolic and diastolic pressure


In my practice, I frequently use a nutritional formula called Elemental Select from Moss Nutrition to help patients prolong fasts and see similar results. An elemental formula is one in which fats, proteins and carbs are broken down so that they are efficiently and quickly absorbed high in the GI tract. This gives the majority of the small intestine and all of the large intestine a break, in similar fashion to a fast.

I ask patients to begin fasting by skipping breakfast, and drinking only coffee, tea or bone broth. Then, when they begin to get hungry, they use a serving of Elemental Select, blended with ice and 1 Tbsp of coconut oil, avocado or olive oil for additional calories in the form of fat. I find that this helps further reduce hunger in comparison to drinking the formula by itself, which can also be done. They then slowly sip on the shake for the remainder of the day. One scoop of formula + 1 Tbsp of oil comes out to roughly 400 calories.

All in all, this strategy allows me to be confident that my patient is getting high quality nutritional intake on their fasting days. It helps my patients by making fasting easier, and helps them to be sure that they aren’t overeating. It is also very convenient and saves them time that would have been spent on meal prep.


Are Elemental Formulas Safe?

Absolutely. Elemental formulas have been used to support nutrition and heal the gut in patients with inflammatory bowel disease for years. More recently elemental diets have gotten popular as they’ve been proven effective in treating more common GI conditions like SIBO, SIFO and dysbiosis. These studies have consistently shown that these formulas are safe and effective.

As one example, a group of Japanese patients who were hospitalized for Crohn’s Disease were sent home on a “half elemental diet” where half their calories came from a regular diet and half from an elemental diet. The study was designed to track the long term safety of using partial elemental diets. Although these patients had bad enough inflammatory bowel disease to be hospitalized, there were no adverse effects and no problems with the group relying on elemental formula for a major part of their diet. In fact, although researchers planned to follow the groups for 2 years, the trial was actually stopped after 1.5 years after it became clear that the elemental diet group were doing much better than the regular diet group. The relapse rate was nearly 64% in the regular diet group, but only 35% in the Elemental group - strong evidence that Elemental formulas are both safe and effective.

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