When cutting down, especially for a bodybuilding contest, hunger pangs can be unbearable at times. In turn, everyday tasks become daunting, stress increases, and sleeping is highly difficult. For the majority of those on a low-carb/low-calorie diet, some hunger will be inevitable, but it doesn’t have to be excruciating all the time.
Therefore, this article will discuss how hunger signaling works physiologically. You will also learn how to use that understanding to curb hunger pangs that arise from energy-restrictive dieting.
Before diving into the physiology of hunger signaling, it's pertinent to make a distinction between the terms hunger and appetite. Appetite is typically a more appropriate term for psychological cravings for food; hunger, on the other hand, is the body’s physiological signaling that it wants food. Therefore, if you happen to have just packed away a wholesome meal and stumble across a commercial for a Dairy Queen blizzard, odds are your appetite is taking precedent over satiety cues. America is one of the few countries where most people simply lack the psychological willpower to resist food temptations (because we often eat for pleasure and “fun”). There’s not really much complexity to appetite.
On the contrary, hunger signaling is an intricate system, particularly in lean individuals and those who are excessively overweight. The neuroendocrine system is largely responsible for modulating hunger in humans; hormones secreted in the gut and pancreas, particularly ghrelin, increase feelings of hunger rather rapidly.[1]
When ghrelin binds to receptors in the gastrointestinal tract, growth hormone (GH) secretion increases from the pituitary gland in the brain.[2] GH is primarily thought to be a ‘mobilizing’ hormone, in that it stimulates lipolysis and fatty acid oxidation when the body is depleted of energy (i.e. hunger is elevated).
Shortly after eating begins, both GH and gherlin stimulate neurons in the hypothalamic region of the brain that release a chemical called neuropeptide Y (NPY).[3] Expression of NPY goes on to produce feelings of pleasure and satisfaction, largely due to increase of dopamine in the brain.
As you continue eating, anorexigenic peptides, such as glucagon-like peptide 1 (GLP1) , cholecystokinin (CCK), and leptin being secreting satiety (fullness) signals.[4] You’ll often hear dietitians recommend you eat slowly as this permits these satiety signals to kick in before you overeat.
This rudimentary overview of neuroendocrine signals gives us a chance to better understand how to curb hunger cues effectively.
The most prudent, and simple, way to decrease hunger pangs is simply increasing soluble fiber intake. The key here is making sure you ingest sufficient soluble fiber as opposed to insoluble fiber. Adding soluble dietary fiber to meals significantly reduces blood glucose and subsequent insulin response.[5] Research shows that soluble dietary fiber is drastically more effective than insoluble fiber at achieving lower insulin responses and decreasing feelings of hunger.[6] This appears to come from soluble fiber’s viscous nature, since it binds with water to form gel-like substances in the gastrointestinal tract and slow digestion.
The additional benefits of slower nutrient absorption include improvements in glucose tolerance and lowering of serum cholesterol levels. Moreover, delaying carbohydrate absorption brings about a lower post-meal blood glucose level. In general, the more viscous the fiber, the greater the post-meal blood glucose reduction.
This is similar to the metabolic effect of eating several smaller meals throughout the day rather than one or two large meals. When carbohydrates are eaten in small amounts over an extended period, the insulin response is attenuated.
Adding fiber to every meal can make a huge impact on hunger. If you’re looking for something during contest prep dieting, psyllium husk and/or apple pectin capsules do a great job at gelling up in your stomach. Psyllium is a soluble dietary fiber extracted from Plantago ovata. The dried ripe seeds of Plantago ovata contain mucilage in their outer epidermidis and swell upon contact with moisture.
The hydrophilic (water-loving) properties of psyllium (each gram of psyllium retains about ten grams of water) leads to the formation of a highly viscous gel. As a result, psyllium is able to pick up hydrophilic molecules, such as simple carbohydrates (i.e. disaccharides) and proteins, and retain them in the stomach in a manner similar to that demonstrated with pectin.[7]
This, in turn, results in a more uniform presentation of the meal to the small intestine for absorption. The psyllium-induced delay in intestinal absorption of energy modifies the characteristics of the meal. In general, the glycemic index of a food or glycemic load of the entire meal will decrease significantly. Furthermore, feelings of hunger will decrease and satiety will increase.
Poorly soluble (insoluble) fibers that do not form gels, such as wheat and cellulose, have little effect on hunger and satiety as they pass through the digestive tract rather unabsorbed (in fact, it speeds up digestion and frequency of bowel movements). Oats, legumes, veggies, and fruits tend to be good sources of soluble fibers.
The tips below can assist increased fiber consumption to further combat hunger pangs that arise from calorie-restrictive diets.
Using over-the-counter acid reducing drugs, such as Prilosec, can reduce intense bouts of hunger caused by stomach acid by inhibiting proton pumps.
Can work in a similar method to stomach acid reducers, but may cause constipation Antihistamines should be used sparingly; a common example is Benadryl (diphenhydramine), which many bodybuilders use to sleep when insomnia is an issue.
Carbonated water increases gas (air) in the stomach, which causes the abdomen to expand. In turn, feelings of fullness increase. Be careful not to drink carbonated water too close to competition time as it can induce bloating and stomach distention.
Coffee, the most popular source of caffeine, is a diuretic and also tends to decrease hunger cues. Since caffeine increases urinary frequency, you’re more likely to drink more fluid, which can also reduce hunger pangs. Green tea is another good, natural source of caffeine.
Certain amino acids, such as phenylalanine, work to increase CCK levels (recall from earlier this is an anorexigenic peptide hormone). Typically, as little as one to two grams of racemic (DL)-phenylalanine will be sufficient for a few hours of reduced hunger.
Hopefully this article has given you some better insight into how hunger works physiologically, as well as how you can curb hunger signals when dieting. The most efficacious method, by far, is to increase soluble fiber intake. If you’re not a big fan of veggies and fruits, supplemental apple pectin and/or psyllium husk is the way to go.
[1] Spiegel, K., Tasali, E., Penev, P., & Van Cauter, E. (2004). Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of internal medicine, 141(11), 846-850.
[2] Higgins, S. C., Gueorguiev, M., & Korbonits, M. (2007). Ghrelin, the peripheral hunger hormone. Annals of medicine, 39(2), 116-136.
[3] Chen, H. Y., Trumbauer, M. E., Chen, A. S., Weingarth, D. T., Adams, J. R., Frazier, E. G., ... & Ye, Z. (2004). Orexigenic action of peripheral ghrelin is mediated by neuropeptide Y and agouti-related protein. Endocrinology, 145(6), 2607-2612.
[4] Woods, S. C. (2004). Gastrointestinal satiety signals I. An overview of gastrointestinal signals that influence food intake. American Journal of Physiology-Gastrointestinal and Liver Physiology, 286(1), G7-G13.
[5] Würsch, P., & Pi-Sunyer, F. X. (1997). The role of viscous soluble fiber in the metabolic control of diabetes: a review with special emphasis on cereals rich in β-glucan. Diabetes Care, 20(11), 1774-1780.
[6] Salmeron, J., Manson, J. E., Stampfer, M. J., Colditz, G. A., Wing, A. L., & Willett, W. C. (1997). Dietary fiber, glycemic load, and risk of non—insulin-dependent diabetes mellitus in women. Jama, 277(6), 472-477.
[7] Goñi, I., & Martin-Carrón, N. (1998). In vitro fermentation and hydration properties of commercial dietary fiber-rich supplements. Nutrition Research, 18(6), 1077-1089.
