Often we eat and then follow up that meal with a snack, and can sometimes fit in another snack before our next meal. Why do we do this and how can we control hunger when we're on keto? We deep dive into why we feel hunger and how a ketogenic diet can help improve health markers.
Controlling Hunger on a Ketogenic Diet
Have you ever wondered why you might often feel hungry soon after eating a meal? Or maybe you can just keep eating and never really feel full? A bowl of pasta with a side of garlic bread followed by a piece of cake with a cup of coffee is a common story for many.
And then there are those people who just seem to snack all day.
A recent survey found that nearly 40% of Australians snack between meals during the day (1). Another survey showed that more than a quarter of adults are considered heavy snackers (2).
Being constantly hungry and then overeating can lead to several health concerns including insulin resistance, altered blood sugar levels, obesity and type 2 diabetes. A 2017 study found that a single day of binge eating compromised insulin sensitivity and impaired glucose metabolism in young, healthy adults.
While these facts might not be surprising, what may raise eyebrows is that what is being described here isn’t hunger, it’s appetite, and there is a difference. Hunger is the uneasy sensation caused by a lack of food. Appetite refers to the desire to eat and, in this context, is associated with cravings that are often unrelated to calories and more about emotions, hormones and the types of foods being eaten.
What can I do if I’m an emotional eater?
Emotional eating is a pattern of behaviour that typically develops during the first years of life. During this time, children learn to associate the desire for food with certain emotional experiences, both positive and negative.
Emotional eaters tend not to reach for healthy foods but rather prefer to consume very tasty energy-dense, high-sugar snacks which provide an instant feeling of pleasure or satisfaction.
However, recent studies have shown that while emotional eating patterns may initially be formed in childhood, overeating and the regular consumption of snacks is also strongly associated with habit and dysregulated hormones (4).
In addition to this is the fact that the snacks and processed foods that make up so much of our modern diet are not only addictive by design, but are also empty simulations of food, providing little-to-no nutritional value, leaving us constantly craving more.
While this may seem like a hopeless situation, knowing what drives our incessant food cravings also means we can start addressing some of the underlying causes.
How can a keto diet help?
When you eat a meal heavy in carbohydrates this causes a spike in your blood sugar levels in the form of glucose.
Your pancreas then releases insulin which helps move that glucose out of your bloodstream and into your cells. Some glucose will be used for energy and any that is left over will be stored as fat.
The energy from that meal, however, might be short-lived. With no more glucose in your bloodstream you might soon be desiring more carbohydrates and reaching for a snack. Your body will also be quite unaccustomed to burning fat for energy, so it is not going to be very efficient at tapping into those fat reserves. This leaves you on a never-ending rollercoaster ride of fluctuating blood glucose levels and carbohydrate cravings.
By contrast, a ketogenic diet is a low-carb, high-fat diet that allows the body to become adapted to burning fats instead of carbohydrates to produce energy.
By shifting your focus away from carbohydrates and increasing your consumption of healthy fats and quality protein you will be consuming more nutrient-dense foods that not only better nourish your body but also help you feel full.
A ketogenic diet allows your body to go into a metabolic state known as ketosis. When this happens, your liver becomes well adapted to converting fats from your diet, as well as fats stored in your body, into ketones for energy.
This not only improves your ability to burn fats and lose weight, but also positively impacts your sense of satiety.
Ketones have a direct effect on appetite hormones
There are several hormones that control appetite and grhelin, otherwise known as the ‘hunger hormone’ plays a key role. This hormone is produced in the gut and then travels through the bloodstream to the brain, producing hunger signals and the urge to seek out food (5).
The higher your blood levels of grhelin are the hungrier you will feel.
Higher ketone levels during a ketogenic diet cause a reduction in the production of ghrelin. This causes you to feel more full resulting in less snacking and a reduction in total food intake.
Interestingly, hormones such as leptin, which suppresses appetite and makes you feel full, are also reduced during ketosis. You might think that this would cause your appetite to increase but, it turns out that when you are in ketosis your brain’s sensitivity to leptin goes way up. This increased sensitivity to leptin also dampens the effects of dopamine in your brain, making snacks less rewarding and reducing your motivation to keep eating (7).
Ketones also stimulate the production of other satiety hormones such as GLP-1 and CCK (8).
Nutritional ketosis, inflammation and appetite
When we eat a carbohydrate rich diet our cells can become resistant to the effects of insulin. In response, the pancreas releases more of this hormone, which triggers the body to store fat. This accumulation of fat, particularly abdominal fat, results in an increased production of inflammatory markers that reduces the brain’s sensitivity to leptin.
A ketogenic diet has been shown to control inflammation by influencing a dramatic reduction in inflammatory biomarkers such as total white blood cell count, CRP, and pro-inflammatory cytokines. It has also been observed that ketosis may positively impact the type of brain inflammation that contributes to diet-induced leptin resistance and resultant weight gain (9, 10).
This means that the anti-inflammatory properties of nutritional ketosis can be directly linked to improved satiety and reduced cravings (11).
Ketones, gut bacteria and appetite
Research has shown that a variety of proteins, hormones and neurochemicals produced by our gut bacteria influences the regulation of our appetite. By mimicking our own appetite hormones, these bacterial products can cause specific cravings that can dictate our food choices.
As strange as this might seem, it does make sense that the microbes that live in our gastrointestinal tract would have strategies for influencing what we eat. After all, the food we eat is also food for our bugs.
It has been observed that gut bacteria can generate cravings in us for foods that they prefer and foods that suppress their competitors as well as inducing a state of unease until we eat foods that enhance their fitness (12).
Fortunately, we also know that our gut bacteria can be changed by our dietary choices. If we eat a diet high in simple carbohydrates, we will be promoting the types of gut bacteria associated with inflammation, obesity and dysbiosis. In turn, these bacteria will contribute to increased cravings for carbohydrate-rich foods.
On the other hand, the beneficial effect of a ketogenic diet on metabolic health, including appetite control, increased insulin sensitivity, and weight are likely, at least in part, mediated via the gut microbiome.
What if I’m still feeling hungry on ketosis?
Appetite and hunger are a complex set of processes that involve many influencing factors. Even if you are in ketosis, that doesn’t mean that you won’t experience cravings and the temptation to snack.
Nevertheless, there are some effective ways to reduce these that are both satisfying and keto-friendly.
- Make sure you are eating enough fat. Being much more energy-dense than carbohydrates, fats are also more satiating. They will also ensure that you stay in ketosis.
- Increase the size of your meals with nutrient-dense foods. This will promote a sense of fullness and reduce the urge to snack in between meals.
- Include plenty of fibre in your meals. While fibre from foods like green leafy vegetables is considered a carbohydrate, we don’t digest it, so it doesn’t count. It will however contribute to a sense of feeling full and promote satiety inducing gut bacteria.
- Stay hydrated by drinking plenty of water. There is a tendency to lose water in the early stages of ketosis, which can contribute to keto flu symptoms. A belly full of liquid will also help make you feel full.
- Don’t overlook the importance of sleep. When we don’t get enough sleep, we release the stress hormone cortisol. This mobilises stored glucose into the blood stream which can increase cravings and makes maintaining ketosis a challenge.
The bottom line:
Starting a ketogenic diet can be a challenge. After all, you are changing your diet so that your body can learn a new way of metabolising and producing energy. The benefits of this are improved metabolic wellbeing, weight loss and appetite control.
The downside can be the transition into ketosis. For some this can take a week or two, during which time you may contend with cravings, hunger, and even keto flu. However, once your body adjusts, you’ll be amazed at how sustaining a ketogenic diet can be.
- Euromonitor International Voice of the Consumer: Lifestyles Survey 2022, https://www.euromonitor.com/article/the-snacking-revolution-in-australia
- Article No. 8272, https://roymorgan-cms-dev.s3.ap-southeast-2.amazonaws.com/wp-content/uploads/2022/04/12232254/8272-Packaged-Snack-Foods-February-2020.pdf
- Parry SA, Woods RM, Hodson L, Hulston CJ. A Single Day of Excessive Dietary Fat Intake Reduces Whole-Body Insulin Sensitivity: The Metabolic Consequence of Binge Eating. Nutrients. 2017 Jul 29;9(8):818. doi: 10.3390/nu9080818. PMID: 28758920; PMCID: PMC5579612.
- Marieke A. Adriaanse, Denise T.D. de Ridder & Catharine Evers(2011) Emotional eating: Eating when emotional or emotional about eating?, Psychology & Health, 26:1, 23-39, DOI:1080/08870440903207627
- Müller TD, Nogueiras R, Andermann ML, Andrews ZB, Anker SD, Argente J, Batterham RL, Benoit SC, Bowers CY, Broglio F, Casanueva FF, D'Alessio D, Depoortere I, Geliebter A, Ghigo E, Cole PA, Cowley M, Cummings DE, Dagher A, Diano S, Dickson SL, Diéguez C, Granata R, Grill HJ, Grove K, Habegger KM, Heppner K, Heiman ML, Holsen L, Holst B, Inui A, Jansson JO, Kirchner H, Korbonits M, Laferrère B, LeRoux CW, Lopez M, Morin S, Nakazato M, Nass R, Perez-Tilve D, Pfluger PT, Schwartz TW, Seeley RJ, Sleeman M, Sun Y, Sussel L, Tong J, Thorner MO, van der Lely AJ, van der Ploeg LH, Zigman JM, Kojima M, Kangawa K, Smith RG, Horvath T, Tschöp MH. Ghrelin. Mol Metab. 2015 Mar 21;4(6):437-60. doi: 10.1016/j.molmet.2015.03.005. PMID: 26042199; PMCID: PMC4443295.
- Roekenes J, Martins C. Ketogenic diets and appetite regulation.Curr Opin Clin Nutr Metab Care. 2021;24(4):359-363. doi:10.1097/MCO.0000000000000760
- de Git, KCG., Adan, RAH. Leptin resistance in diet-induced obesity: the role of hypothalamic inflammation. Obesity Reviews. 2015; 16: 207–224
- Martins C, Nymo S, Truby H, Rehfeld JF, Hunter GR, Gower BA. Association Between Ketosis and Changes in Appetite Markers with Weight Loss Following a Very Low-Energy Diet. Obesity (Silver Spring). 2020;28(12):2331-2338. doi:10.1002/oby.23011
- Forsythe CE, Phinney SD, Fernandez ML, et al. Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation. Lipids. 2008;43(1):65-77. doi:10.1007/s11745-007-3132-7
- Bhanpuri NH, Hallberg SJ, Williams PT, et al. Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study. Cardiovasc Diabetol. 2018;17(1):56. Published 2018 May 1. doi:10.1186/s12933-018-0698-8
- Gibson AA, Seimon RV, Lee CM, et al. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obes Rev. 2015;16(1):64-76. doi:10.1111/obr.12230
- Alcock J, Maley CC, Aktipis CA. Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. Bioessays. 2014;36(10):940-949. doi:10.1002/bies.201400071