John Kiefer is a fitness trainer.

He originally wrote for Elite FTS and now does so for

His posts on breakfast explains the state of our body’s hormones early in the morning and how breakfast can hamper fat burning.

In fact, he advises his clients to not eat breakfast. His reasons follow.

One of the best-known statements in support of breakfast is that it helps to burn more calories during the day. In ‘Eating Breakfast Causes Weight Loss: Worst Research Ever’ (language alert) Kiefer discusses a 2013 NPR (National Public Radio) programme on the subject in light of a Spanish study:

from the International Journal of Obesity stating that subjects who ate their main meal of the day before 3 PM lost significantly more weight than people eating later in the day—with calories consumed in both groups being roughly equal.

The study contrasted diet results of breakfast-eaters versus those who took their first meal later in the day.

Kiefer points out that the type of weight loss between the two groups is important:

what the authors of the Spanish study aren’t telling you … is that their morning group lost weight because they lost significantly more muscle. This study tests body fat at the very beginning, but conveniently never mentions again, referring only to weight.

In ‘Logic Does Not Apply Part 2: Breakfast’, Kiefer explains hormone activity in our bodies at 7 a.m. and how eating breakfast can affect it, not always for the better.

Cortisol helps to burn fat and builds up while we sleep, peaking around the time most people are getting up:

Cortisol, when acting without elevated insulin levels and in a natural manner — so without being constantly elevated like during chronic stress — triggers the breakdown of triglycerides into free-fatty acids (FFAs) for metabolization and triggers lipolysis1, 2, 14-28. Cortisol, in the morning, accelerates fat burning.

Ghrelin nears its peak at this time. Ghrelin controls hunger and the release of growth hormone:

As growth hormone levels raise the body releases more fat to be burned as fuel45-49 and decreases the destruction of protein for use as fuel50. Growth hormone levels peak roughly two hours after waking without breakfast51.

Therefore, we wake up with bodies ready to burn fat:

Every day the body starts as a fat-burning furnace. Even during exercise, without eating breakfast, the body burns far higher levels of fat than normal52, 53 and causes up regulation of the enzymes necessary to burn fat, allowing fat to be metabolized faster54.

The average Westerner interrupts this process with breakfast, especially if it has 30 grams or more of carbohydrate. Carbs break down into sugars. Kiefer explains (emphases mine):

As is well known, insulin levels raise with the rise in blood sugar, kick-starting a downward spiral: the early-morning release of insulin reduces fat burning for the entire rest of the day55; … and the insulin lowers levels of ghrelin and growth hormone29-31, 51.

Going back to the aforementioned Spanish study, the breakfast eaters lost weight in the form of muscle. Those who refrained from eating until late morning or lunch lost fat.

A good weight loss regime should burn fat, not muscle.

Incidentally, this is what the difference in volume between fat and muscle looks like (photo credit — Show Up Fitness):

Breakfast skippers may be on to something without realising it. Their lack of hunger may indicate that their bodies are ready to do what is normal in the morning: burn fat. Nourishment can comfortably come later.