Your daily nutritional / dietary timing has significant underlying impact on your hormonal balance. Because hormones drive metabolic pathways, it is absolutely essential the athlete only consumes no more than 3 meals a day and NO snacks in their daily diet. This does not include any in training/racing fueling around or during long duration training/racing. While this counters much of the conventional advice of 5-6 small meals a day, it makes perfect sense for the fat-adapted athlete. Many well-adapted OFM athletes find themselves comfortably consuming 1-2 full meals a day once fully adapted. After the evening meal no snacks or desserts. This pattern of daily eating should be easy and relatively effortless for an OFM athlete because they are not being held hostage by food (carb) cravings. For athletes who are segueing into OFM it is recommended they consume a pouch of VESPA at 9 am and 2 pm in their daily life instead of a snack at 10 am and 3 pm to “jump-start” fat metabolism and mitigate the hunger trigger for a snack for the first two to three weeks. Further reading on Intermittent Fasting is recommended to further enhance you OFM potential. For those who question or are curious as to why OFM prescribes no more than 3 meals a day and, ideally, 2 meals or less per day instead of the 5-6 times a day here is why………. There are 2 principle areas which, when understood, make is clear why it is much healthier to consume no more than 3 meals a day rather than the 5-6 many sports nutritionists are recommending. The first is the complicated dance between the 3 principle hormones of hunger and satiety which go on when a person consumes a meal; insulin, leptin and ghrelin. While this overview is vastly oversimplified it does give the general public a basic understanding of why timing and frequency are so important to OFM nutrition….
Insulin is produced principally in the pancreas and is secreted when blood sugar levels rise, normally when a meal is consumed which has enough carbohydrate content to trigger a rise in blood sugar to what the body perceives as a “toxic” level. Like most all hormones insulin is multi-functional but one of its primary jobs is to immediately drive blood sugar down when elevated. As any Type 1 diabetic will tell you chronically high blood sugar is toxic and will kill you. A T1 diabetic injects the appropriate insulin dose when consuming carbohydrates in any significant amount, people who are not diabetic have it done automatically by their pancreas. However, when this happens a whole set of physiological pathways are set in motion to drive blood sugar down, even in a fat adapted athlete who consumes some level of carbohydrates. The higher the insulin load the greater the negative impact on the body’s ability to metabolize fat in a variety of ways.
Leptin is principally produced in adipose (fat) tissue and is released when the fat cells sense a surge in deposition which circulates to receptors of the hypothalamus in the brain basically signalling satiety (fullness). Now when everything is in balance this signal works well and plays a crucial role in maintaining that homeostatic balance to regulate energy levels, weight, and endocrine balances, however, it is very easy for the body to develop leptin resistance, particularly in females as, in general, tend to secrete 2-3 times the leptin over most males. When this occurs the hypothalamus does not “see” the leptin, thus does not sense satiation so the person will physiologically be hungry. This physiology is VERY difficult if not impossible to overcome through sheer will power over the long term. Research also suggests leptin resistance plays a key role in the obesity epidemic, however, researchers are still not clear on the exact mechanisms which trigger this condition. So the goal is to retain leptin sensitivity. Through extensive research and empirical work with OFM athletes one aspect is that of Daily Nutritional/Dietary Timing. The conventional frequency of feeding advice is well-intended but has unintended consequences which can tend toward the development of Leptin Resistance because of the constant leptin signalling the hypothalamus receives. Thus strategies of no more than 3 meals and eventually 2 meals or less along with periods of Intermittent Fasting are doable ways to sharpen leptin sensitivity which will enhance OFM.
Meanwhile down in the stomach and gut the hormone ghrelin is the third major hormone regulating hunger and satiety. Ghrelin levels are highest when we have those hunger cravings and lowest after a full meal. Additionally, ghrelin has been shown to be controlled by body composition, Circadian rhythmn, a host of peptides, hormones and and enzymes in the stomach and gut where it is produced and has a role in Growth Hormone release and proper endothelial function. So it has been somewhat complicated for researchers to deduce and parse out an understanding of ghrelin in terms of a detailed understanding. What has come out is that it is the acylated form of ghrelin which is thought to be able to cross the blood brain barrier to reach the hypothalamus and stimulate hunger triggers. Exercise, Intermittent Fasting and LC/HF diets tend to suppress this acylation, thus suppressing the hunger triggering of ghrelin.