I would love some insights into the following scenario so I can get a better understand of what factors might influence appetite the most. There are some very well informed biology minded folks here so I’d love some ideas from that perspective. Here is my current situation: Some days I am able to fast until around noon or 1 or even later in the day, including a workout in the morning (running or running and weight lifting, usually an hour or so total). I don’t experience hunger and my energy level is good. Other days, I can’t make it past 9 or 10 without eating, and then if I eat, I don’t have a great workout and I tend to get tired and a bit nauseated. Here are some factors that I know influence one’s ability to fast for longer periods- my body fat level is very low for a woman, at 12%. This has a direct effect on leptin levels, and my estrogen levels are low too, and I know the status of both of those hormones greatly influences appetite. I tend to eat dinner around 6 which is usually a good sized portion of fatty meat and veggies with added fat. I also will have a couple of servings of Ultima electrolyte drink during the day (no sugar, sweetened with stevia, high quality product). This helps my energy and hydration levels. Lately after dinner I have been feeling hungry still but usually talk myself out of eating more because I think I have eaten a sufficient amount and worry the hunger is “psychological” so I don’t want to fall into the trap of eating for reasons other than true physical hunger. However, my stomach rumbles, I feel less relaxed, the pangs aren’t overpowering but they are definitely noticeable. I know from previous experience on keto, when I got very, very lean, even leaner than I am now, that the body will really ramp up hunger signals when it senses energy stores are getting low. I’m not sure if that is what’s going on here or if there is some other factor. I have considered that the electrolyte drink might be increasing my hunger, but it is made from stevia which doesn’t really affect blood sugar, though the flavor is certainly very appealing and my taste buds really crave it. Am I eating too much protein? This is possible but I feel that i eat an appropriate amount given my lean body mass and level of activity. I do not eat dairy, I do not have “keto” treats or desserts. I have observed that when I do eat additional food in response to the evening hunger signals, in the form of things including raw macadamia nuts, sprouted raw almonds, maybe some coconut butter or raw nut butter, the hunger is not there in the morning. Is my body clearly telling me I need the additional energy, especially fat, since I am quite lean and cannot draw on my body fat stores for energy to the extent that others who have larger stores can? Should I be worried the electrolyte drink is stimulating appetite? I eat a very clean and nutrient dense keto diet and I do have a good amount of veggies at dinner as well. Can veggies induce hunger to this extent? I am trying to figure this out so I can fuel my body appropriately and prevent any more loss of body fat. But I also worry about the ominous “emotional eating”, despite my observation that this hunger feels very physical in origin. Long post…but I needed to include all those details to address any possible triggers of my increase in appetite. Thanks!
Appetite mysteries!
I agree that hunger is a complicated issue since it is influenced by our physical and emotional environment, so it’s often hard for me to tell them apart while in the middle of it. Hindsight can often tell me that I was really just looking for comfort food or experiencing the “hormonal entrainment” of expecting to eat at certain times.
I quoted the part of your post that I think is probably the most common reason for feeling hungry as I’m at about 18% bodyfat, but given the nature of the way I measure using BIA, it could be closer to the 12% that you report.
Another issue that I bring up occasionally is from an endocrinologist named Dr. Diana Schwarzbein. I’ve read her books and she points out that healing damaged metabolisms will often take many years and result in increased weight while the body is repairing itself since the side-effect of the anabolic mechanisms is often increasing food intake.
In other words, you might be physically hungry because your body is actively fighting the onslaught of a bacteria or virus before it results in symptoms, or in the building-up phase after a fast where your body is replacing the old structures with new ones through autophagy. In other words, some of the the benefits of fasting don’t come during the fast, but from the rebuilding that comes after autophagy scavenges the old structures and needs to build the new ones.
There’s also thermogenesis where your body needs calories to raise your temperature when the external temperature drops as in winter.
http://www.schwarzbeinprinciple.com/pgs/home.html
For example, it’s colder than normal here in Florida USA, so I’ve found that I’ve been hungrier than normal and instead of having 1 - 2 tablespoons of marscapone cheese with my breakfast, I ate the rest of the container and no longer feel hungry or cold like I did at the time.
Keep us updated if you have any insights into your hunger!
Although your electrolyte drink might not be affecting your BG, for some sweetness of any sort can trigger cravings. [quote=“Emacfarland, post:1, topic:5085”]
I have observed that when I do eat additional food in response to the evening hunger signals, in the form of things including raw macadamia nuts, sprouted raw almonds, maybe some coconut butter or raw nut butter, the hunger is not there in the morning.
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I know it’s a pain to track everything but you may want to track everything you eat and when you eat it. You may see on nights you have a lower intake, you are hungry earlier in the morning, on days that you have larger evening meals you can go longer. I believe this would be a clear indication you are not taking in enough nutrition to meet needs.
Oh good info!! Of course there is not definite or singular answer but hearing all these factors that influence our hunger levels helps piece the puzzle together. I absolutely experience a kind of coldness/shivery feeling when I have the strong hunger signals, but I have lived in Colorado my whole life so am pretty used to the cold! I wanted to add that my previous experience on keto could probably be an entire blog post in itself because it was a very complicated situation that ultimately resulted in very poor health, but in hindsight there were many problems in my approach that I was unaware of at the time. So my second venture into keto has been much better informed, particularly because this podcast was not around my first time and I have learned SO much about how to implement keto without deleterious side effects. As a quick synopsis I ended up getting dangerously lean, 6% body fat, though I had no idea this was dangerous until a trainer at my gym told me my organs could shut down. Looking back the signs that i was underfed were there but I didn’t recognize them at the time. So this go round I am acutely aware of my body telling me I need more fuel. Particularly as a woman, sex hormones are very sensitive to energy reserves, and I believe I have lost my cycle again after 4 months in on my second round of doing keto. This tells me I am not sufficiently fed which may be one reason for the increased hunger signals. I wonder too, in reference to your point about healing metabolism, if because my body was put through what was essentially starvation, it is particularly aware of lower levels of body fat and is ramping up signals to get more energy. However I have at times in my life been heavier, never diabetic or IR but certainly I could probably have ended up with those illnesses had I kept up a high carb intake and lower activity level. Both of those diseases run on my mom’s side so I am determined to avoid them like the plague. So finding a place where I can do keto sustainably is tricky for me given my history.
I am going to try and write down my reactions so I can get a better idea of what influences these different outcomes. And sadly it might mean not gulping down my yummy grape electrolyte drink!! 
How long have you been keto? I can tell you from my experience that during the first 4-6 months as I became fat adapted I had way more hunger cravings. I was in ketosis but required way more keto snacks then I do now. I would regularly do 24 hour intermittent fasting and some days I would struggle a great deal, and others not so much. On the days I was not fasting I snacked on a lot of cheese, bacon and butter or HWC in the coffee. After that first 4-6 months I found that my hunger signals decreased drastically. I assume that was the point when I became 100% fat adapted. Dr. Stephen Phinney has pointed out in his lectures that some people can become 100% fat adapted in several weeks while some take several months. We are all a little bit different.
I Freaking love Grape. I drink grape koolaid sweetened with stevia every night with dinner.
@Emacfarland. Have you checked out the website http://www.nourishbalancethrive.com/
I ask because they work with athletes and use a keto approach. I’ve heard Chris Kelly speak (he helped put together the Keto Summit a while ago) and was very impressed. They may be able to give you some insight into your particular situation. Just a thought. 
It’s crazy, I’ll eat about a pound of fatty burgers with bacon and it’s like nothing went in my stomach 