Pros and Cons of Intermittent Fasting Flashcards
general summary:
Here is a general summary:
Fasting is simply a period without consuming calories. Note that it is intermittent fasting; the name implies infrequency.
Not eating for an extended period is a stress. Fasting is a stress whose severity is dictated by the length of the fast, but stress itself is not inherently good or bad.
Intermittent fasting does not include a prescription of specific foods to eat when not fasting, nor does it control the number of calories consumed when not fasting. The term “time-restricted feeding” is sometimes used to specify fasting without a caloric deficit.
A few of the potential benefits include improved:
A few of the potential benefits include improved:
Body composition (metabolic flexibility).
Health (hormonal control).
Psychological effects
advantages
Once I became used to the shorter feed window, my calories increased and body composition remained unchanged.
is likely people will eat less than their usual volume unless they are tracking their intake. It is harder to eat your daily caloric load in a shorter period, so intermittent fasting might indirectly reduce total consumption, resulting in weight loss. This was my general experience; I essentially droppe
promotes more fat burning, even in the presence of the same daily caloric load.
Some promote intermittent fasting as a way become “metabolically flexible”
rossFit athletes metabolic flexibility allows for greater reliance on carbohydrates near workout times (due to the necessity for high intensity) and greater reliance on fat otherwise (i.e., “fat-adapted”).
Disadvantages
ing does not improve body composition when the body is starving. For someone who is under eating—intentionally or not—the body shifts more to muscle catabolism versus fat burning. Chronic stress, such as starving, increases cortisol. Chronically elevated cortisol can elevate blood sugar and in turn elevate insulin, which ultimately shifts the person away from fat oxidation.
Health (Hormonal Control)
Intermittent fasting brings some potential health benefits via better hormonal control—particularly insulin sensitivity..
health because insulin resistance is present with many chronic diseases (e.g., heart disease, diabetes). Once people develop insulin resistance, they are metabolically inflexible; i.e., they cannot access existing fat stores and become increasing poor at carbohydrate metabolism (i.e., dysglycemia).
dysglycemia).
they cannot access existing fat stores and become increasing poor at carbohydrate metabolism
Disadvantages
intermittent fasting might add too much stress. Someone who already has high cortisol does not need to be fasting; it will only make things worse. Signs of high cortisol include energy levels opposite to a natural circadian rhythm, such as excessive grogginess in the morning and excessive energy at night.
a pioneer in female-specific physiology research, I now understand the monthly cycle of hormonal fluctuations makes fasting less advantageous for women particularly during their high-hormone luteal phase.
net effects of high estrogen and progesterone are protein catabolism and glycogen sparing, which is not good for the CrossFit athlete who wants to gain strength and work out at high intensities. This is exacerbated by high cortisol (stress).
Psychological Effects
Psychological Effects
Benefits
As someone who came from typical mainstream fitness before CrossFit, I found intermittent fasting brought freedom from food. For years I maintained a moderately obsessive meal schedule, eating once every three or four hours. Missing meals was freeing, and the body is not so sensitive that skipping a meal occasionally will result in disastrous metabolic shifts.
Disadvantages
For those who have struggled with diagnosed eating disorders, or even undiagnosed but disordered eating patterns, intermittent fasting is not recommended. It promotes restricting eating that can lead to increased obsession about food “rules.” For someone who has these tendencies, intermittent fasting will likely not create healthy habits.
In Application
The same is true for intermittent fasting. Decide what your goals are (health vs. performance vs. aesthetic) and make an honest assessment of other diet and lifestyle factors. Intermittent fasting is a minor dietary consideration compared to establishing consistency in the quality and quantity of food you eat. If you decide to experiment with intermittent fasting, start small and observe the effects. The overnight fast is particularly easy to implement because it is easily coordinated with our natural circadian rhythm. As length and frequency of fasts increase stress, intermittent fasting will be harder to manage and more likely detrimental to one’s health and performance goals
