The low down on cravings
By The Low Carb Clinic, 22 January 2019 - 662 words (3.5 minutes)
Cravings. A very familiar feeling, especially when trying to lose weight. Certain foods become too hard to resist. You wind up back where you started (or worse).[1]
It’s easy to blame yourself. But contrary to what you may have heard in the past, it is actually not your willpower that is the problem. Your body is actually working against you: producing hormones to defend your original weight and prevent long-term weight loss.[2]
But a low-carbohydrate or ketogenic diet induces a unique metabolic state[3] that addresses these hormones.[4] A low-carbohydrate diet (especially when combined with intermittent fasting) can and will allow for sustainable weight loss[5], by supressing appetite[6] [7]and so reducing debilitating cravings.[8] How?
One: dopamine
High-glycaemic carbohydrates – especially sugar – trigger dopamine release.[9] Dopamine is a hormone of craving, reward and addiction. When we constantly eat things that activate dopamine, our bodies downregulate dopamine receptors, so you require more and more of whatever you are addicted to in order to satisfy the cravings.[10] [11] Just like any drug, cutting these foods will be hard at first. Give your dopamine receptors a bit of time to adjust; but dopamine-led cravings will reduce.
Two: Basal metabolic rate
When you go on a calorie-counting, high carbohydrate, low-fat diet, you restrict the amount of energy you give your body – but you don’t reduce your insulin levels.[12] As long as your insulin levels are high, you’re not able to burn any of your stored energy (glycogen and fat).
Since your body can’t access its stored energy, it compensates by reducing its basal metabolic rate (BMR). This is the amount of energy your body burns, moment to moment. Your body craves the energy from the foods you are trying to cut out.
But a low-carbohydrate diet (especially when combined with intermittent fasting) allows your metabolism to ‘switch’ from carbohydrate burning, to fat burning. [13] Being able to access your fat means that your body has a constantly supply of however much energy it needs – there’s more than 7,000 calories in just one kilogram of fat. Your BMR doesn’t have to drop like it does on a high-carbohydrate, calorie-restricted diet.[14] So if your body isn’t craving energy, then you aren’t going to be craving food.
Three: blood sugar swings
Eating high amounts of carbohydrates causes sudden spikes in blood glucose, but then – because of insulin – sudden drops. We’ve all felt the effects of a ‘sugar crash’ after eating – and we get cravings for more food to fix it.[15] It is a self -perpetuating loop. But eating a low-carbohydrate diet means our blood sugar doesn’t rise to the same extent, so we don’t secrete as much insulin - blood glucose levels stay much more stable, preventing food cravings.
Four: CCK
Another hormone regulating food intake is cholecystokinin (CCK). CCK slows down the movement of food through the gastrointestinal tract, making you feel full, or satiated.[16] Normally, CCK levels fall dramatically with weight loss – so you feel hungrier.[17] However, when you are in ketosis, CCK levels don’t fall – even if you are losing weight.[18] [19] Dietary fat and protein are the main stimulators of CCK; carbohydrates induce very little CCK. [20] So, a diet higher in fat and protein promotes satiety.
Five: ghrelin
Ghrelin is often called the ‘hunger hormone’ because it stimulates appetite.[21] After weight loss, ghrelin levels tend to increase – prompting hunger and cravings – which persist, even after a year. [22] No wonder it is so difficult to “stick” to a diet. However, such changes to ghrelin don’t occur if the body is in ketosis. Ghrelin may still fluctuate to reflect your normal eating patterns[23] – causing hunger, but not the ravenous hunger of a calorie-restricted diet. If combined with intermittent fasting, ghrelin levels can fall even further.[24]
By eating foods that positively influence your hunger hormones, a low-carbohydrate diet will go a long way towards reducing cravings, keeping you on track. Low-carb is the key to sustainable weight loss – and at The Low Carb Clinic, we will work with you to meet your goals.
[1] Leibel, R., Rosenbaum, M., & Hirsch, J. (1995). Changes in energy expenditure resulting from altered body weight. The New England Journal of Medicine, 332(10), 661-628.
[2] Ebbeling, C., Feldman, H., Klein, G., Wong, J., Bielak, L., Steltz, S., . . . Ludwig, D. (2018). Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. British Medical Journal, 363. doi:http://dx.doi.org/10.1136/bmj.k4583
[3] Thio, L. (2012). Hypothalamic hormones and metabolism. Epilepsy Research, 100(3), 245-251. doi:10.1016/j.eplepsyres.2011.07.009.
[4] Anton, S., Moehl, K., Donahoo, W., Marosi, K., Lee, S., Mainous, A., . . . Mattson, M. (2018). Flipping the metabolic switch: understanding and applying health benefits of fasting. Obesity, 26(2), 254-268. doi:10.1002/oby.22065
[5] Ebbeling, C., Feldman, H., Klein, G., Wong, J., Bielak, L., Steltz, S., . . . Ludwig, D. (2018). Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. British Medical Journal, 363. doi:http://dx.doi.org/10.1136/bmj.k4583
[6] Gibson, A., Seimon, R., Lee, C., Ayre, J., Franklin, J., Markovic, T., . . . Sainsbury, A. (2014). Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obesity Reviews, 16(1). doi:10.1111/obr.12230
[7] Sumithran, P., Prendergast, L., Delbridge, E., Purell, K., Shulkes, A., Kriketos, A., & Proietto, J. (2013). Ketosis and appetite mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition, 67, 759-764.
[8] Ebbeling, C., Swian, J., Feldman, H., Wong, W., Hechey, D., Garcia-Lago, E., & Ludwig, D. (2012). Effects of dietary composition on energy expenditure during weight-loss maintenance. JAMA, 307(4), 2627-2634.
[9] Ahmed, S., Guillem, K., & Vandaele, Y. (2013). Sugar addiction: pushing the drug-sugar analogy to the limit. Current Opinion in Clinical Nutrition and Metabolic Care, 16(4), 434-439. doi:10.1097/MCO.0b013e328361c8b8
[10] DiNicolantonio, J., O'Keefe, J., & Wilson, W. (2017). Sugar addiction: is it real? A narrative review. British Journal of Sports Medicine, 52(4), 1-5. doi:10.1136/bjsports-2017-097971
[11] Volkow, N., Wang, Gene-Jack, & Baler, R. (2011). Reward, dopamine and the control of food intake: implications for obesity. Trends in Cognitive Science, 15(1), 37-46. doi:10.1016/j.tics.2010.11.001.
[12] Volek, J., Fernandez, M., Feinman, R., & Phinney, S. (2008). Dietary carbohydrate restiction induses a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Progress in lipid research, 47, 307-318.
[13] Harvie, M., & Howell, A. (2017). Potential benefits and harms of intermittent energy restriction and intermittent fasting amongst obese, overweight and normal weight subjects - a narrative review of human and animal evidence. MDPI - Behavioural Sciences, 7(4). doi:10.3390/bs7010004
[14] Ebbeling, C., Swian, J., Feldman, H., Wong, W., Hechey, D., Garcia-Lago, E., & Ludwig, D. (2012). Effects of dietary composition on energy expenditure during weight-loss maintenance. JAMA, 307(4), 2627-2634.
[15] DiNicolantonio, J., Lucan, S., & O'Keefe, J. (2015). The evidence for saturated fat and for sugar related to coronary heart disease. Progress in cardiovascular diseases, 464-473. doi:http://dx.doi.org/10.1016/j.pcad.2015.11.006
[16] Valassi, E., Scacchi, M., & Cavagnini. (2008). Neuroendocrine control of food intake. Nutrition, Metabolism & Cardiovascular Diseases, 18, 158-168. doi:10.1016/j.numecd.2007.06.004
[17] Chearskul, S., Delbridge, E., Shulkes, A., Proietto, J., & Kriketos, A. (2008). Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations. American Journal of Clinical Nutrition, 87(5), 1238-1246.
[18] Sumithran, P., Prendergast, L., Delbridge, E., Purell, K., Shulkes, A., Kriketos, A., & Proietto, J. (2013). Ketosis and appetite mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition, 67, 759-764.
[19] Chearskul, S., Delbridge, E., Shulkes, A., Proietto, J., & Kriketos, A. (2008). Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations. American Journal of Clinical Nutrition, 87(5), 1238-1246.
[20] Chearskul, S., Delbridge, E., Shulkes, A., Proietto, J., & Kriketos, A. (2008). Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations. American Journal of Clinical Nutrition, 87(5), 1238-1246.
[21] Madusoodanan, J. (2017). Hungering for obesity treatments. American Chemical Society, 3, 150-152. doi:10.1021/acscentsci.7b00101
[22] Sumithran, P., Prendergast, L., Delbridge, E., Purcell, K., Shulkes, A., Kriketos, A., & Proietto, J. (n.d.). Long-term persistence of hormonal adaptations to weight loss. The New England Journal of Medicine, 27, 1597-1604.
[23] Natalucci , G., Riedi, S., Gleiss, A., & Frisch, H. (2005). Spontenous 24-h ghrelin secretion pattern in fasting subjects: maintenance of meal-related pattern. European Journal of Endocrinology, 152(6), 845-850.
[24] Sumithran, P., Prendergast, L., Delbridge, E., Purell, K., Shulkes, A., Kriketos, A., & Proietto, J. (2013). Ketosis and appetite mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition, 67, 759-764.