Calorie deficit

(Luke) #1

This will start some good debate / chat. When I first started keto I truely believe I wasn’t in a calorie deficit , and I dropped weight. This is apparently not possible…I stopped losing right on 10kg down , eating the same amounts and sit around the same weight all the time now.

(Bacon is a many-splendoured thing) #2

It depends on how you define a deficit, but in general terms, your body wasn’t storing all the mass that you were taking in, or you wouldn’t have lost weight. You lowered your insulin by eating a ketogenic diet, and that put you in fat-loss mode. You didn’t feel it, because you were eating to satisfy your hunger.

People make much of the first law of thermodynamics, but as Professor Ben Bikman points out, (a) the human body is not a closed system, and (b) what types of food we eat are much more important to what our body does with the food we eat than our absolute caloric intake.

People have been known to gain fat on half the calories of the other study participants; they have also been known to lose fat while eating nearly twice what the other study participants were eating. Go figure!


Body weight is not equivalent to lean muscle mass. Weight can be lost as water and body fat, and also lean tissue mass if dietary amino acids are not meeting needs. So, it is quite normal to change body weight during a ketogenic way of eating.

Ketogenic eating is more efficient at losing body mass, and subsequently body weight, because not only do we lose atoms as water and carbon dioxide, but we also often start by excreting ketones as well, in urine or on our breath. That’s a lot more carbon atoms going out.

After a period of time we glide into the keto-plateau. That is the time to compare clothes-fit and biomarker tests to the start point. Body weight may even rise as lean muscle mass increases because a keto-fuelled person is often more physically active than a carb zombie.

Oh, calories. Never tasted one that I could write much about.

(KM) #4

I do like Jason Fung’s comment on proximate and ultimate causes. (There’s one gentleman who appears to shed calories simply arguing about CICO). To paraphrase, bringing up laws of thermodynamics in a nutritional discussion is similar to being asked, “Why did the plane crash?” and answering, “Because of gravity”.


If you lost fat, you obviously had a calorie deficit, that’s how it works. But it’s not always trivial to know if we are in a calorie deficit as we can’t possibly know either our CI or CO. Especially not the latter.
And if you choose your woe, more things change than without.

(When I first did keto, I tracked, saw I ate the same as before and unsurprisingly, I lost no fat at all. Sigh. A TINY bonus is something I can explain, why I didn’t get it? :smiley: Too much carbs? But I was in ketosis and anyway, I don’t get a bonus allowance even on carnuivore… Oh well. We do keto, we see if it’s enough and change something if it isn’t. And repeat if needed.)

(Bob M) #6

One of my many theories is that keto helps with hunger for whatever reason, say insulin, say ghrelin, say whatever.

I then think this is why some people are great at losing a ton of weight: their hormones right themselves. Meanwhile, some of us never completely right our hormones back to normal. For instance, I can’t tell you how many times I go home, and am not hungry for dinner. Then eat something small. Then eat more. Then end up eating a normal meal, when starting from not being hungry.

I also think MIMO (mass in, mass out) is probably more true than CICO (calories in, calories out). MIMO is actually based on the rate at which you can lose weight, whereas CICO is based on nothing and has so many holes it becomes useless after a while.

(Doug) #7

We’re almost aways talking about losing fat when we talk about losing weight. However we want to talk about it, to lose fat (short of surgical removal) we need to configure things so that the body starts using its stored fat.

Lowering your insulin level by eating ketogenically can allow your body access to stored fat, as opposed to a high-carbohydrate/high insulin (or high uric acid) diet keeping your body locked in “it’s time to store fat” mode.

Even without using the dreaded “C” word, if you’re still essentially eating “the same amount” and your body now also can access stored fat, that’s a greater pool of energy to draw from, and the body often realizes this and uses more energy. Higher body temperature, maybe you feel a little better overall, do more things or do things a little longer?

That difference from being in “store fat” mode to being in “can use stored fat” is often profound. I lost 60 lbs. in the first 5 or 6 months, and that was with quite a few lapses in my low-carb regimen.

(Chuck) #8

You can create a deficit in calories by eating less calories each day or you can create a deficit by eating your full calories 5 or 6 days of a week and fasting the other day or two.
Or like me you can create a deficit by eating less meals each day and intermittent fasting each day. Now be careful about intermittent fasting and eating each day because it is possible to over eat while intermittent fasting.

(Bob M) #9

How do you know you’ve “created a deficit” by eating fewer calories? Why doesn’t your body just burn fewer calories? Something like this:

They have people cut calories by 25% (CR = calorie reduction), but they only lose 12% because their total daily energy expenditure goes down.

(Bacon is a many-splendoured thing) #10

Whereas Phinney et al. have shown that for people on a low-carbohydrate, high-fat, ketogenic diet, their fatty acid metabolism actually increases, which is another reason it is possible to lose fat while eating to satiety.


It’s clearly not simple, it’s individual and matters how much less below our needs we eat but it’s quite trivial in my case. I know I eat at a deficit because I lose weight and it only can be fat (and a negligible amount of protein. and tiny changes in water and waste so if I lose 500g and I even can measure it, I know absolutely nothing as even my very stable bodyweight can fluctuate that much).
And my metabolism doesn’t slow as I don’t starve myself. A cute deficit is fine, a too big deficit is a problem (not mine, even a tiny one is tricky to get. I automatically overeat if I am free to eat except using some quite strict rules I may or may not have a mood for. As far as I know but my experiences didn’t say otherwise so even if it goes down, it’s not noticeable. And mine goes up way above the original on my high-cal days anyway (it’s possible my metabolism would slow down without those… but probably only long term… but honestly, I don’t know. I think it’s individual that what a body responds to a calorie deficit. I know rare cases lowers metabolism and poor soul feels bad and still lose no fat at 800 kcal… the human body is quite surprising sometimes. I suppose a healthy body with fat to lose doesn’t easily slow down its metabolism, at least not if eating in a small deficit lasts for some weeks. it always gave my SO a slim body in the end, even when he starved, I suppose he is a special case that it worked for him, quickly and moderately easily, still not recommended, obviously. but he got a very quick fat-loss all the way until a quite lean body. some people have that. they probably would die of starvation easier than the ones whose body does everything to stick to the fat reserves…). I don’t KNOW that my body works like I described it but I only can explain my experiences that way (eating way more than usual for a month resulted in no weight gain. I ate much carbs but it doesn’t seem to matter for my body. and I have read that some percentage of the population have this, we can’t gain fat even with massive overeating beyond some very slow pace).

I can do it with little and very, very much food on keto, even on carnivore. Hence my need for extra rules. Food choices and timing matters A LOT.

(Chuck) #12

If you are losing weight or losing inches from your body then you are in a deficit. I eat in short eating window daily, I eat to be satiated and not to be stuffed, I have become so comfortable and accustomed to the feeling of a near empty stomach, that I can’t stand the thought or feeling of being stuffed or even moderately full. My eating window is normally 5 hours or less and I don’t eat near the whole window. I break my fast with either eggs and a meat or my smoothie I create that has fat, protein and even some fiber carbs. What I love about intermittent fasting is how flexible it is and still works.

(Edith) #13

That’s because when you ate that little bit of food, you turned off fat burning mode so your body could prepare itself for incoming food. That’s what appetizers are for. You have a tiny amount of food, it shuts down fat burning by secreting a small amount of insulin and that stimulates your appetite for the rest of the meal to come.


That’s because you were! Caloric deficits are created more than one way, could be your dietary intake, could be your activity (TDEE) etc. Many people over eat, switch to keto, become very satiated (not me) so the drive to under eat is gone and you therefor run a deficit without trying.

The mechanism there is known, although the calories matter, so do hormones. It’s not just one or the other, it’s both. If people don’t track, they typically have no clue what their TDEE is, so impossible for those people to claim they’re in a deficit (or surplus) and you see that on both sides of the spectrum. People that can’t dump fat, and people that can’t gain when they want.

I thought I was in a deficit for months when I wasn’t losing, wound up getting my RMR measured and I was almost eating at a 1000cal surplus. Wasn’t a lot either, but my RMR had slowed down so much it took near nothing to overcome what I was burning.

People will make the argument that Cals In is wrong because of labels not benig perfect, which is true, and that the cals out is very hard to actually measure, which is also true, but that doesn’t change the fact that when you consistently track, the number your working with would have automatically adjusted to that and you’ll still have a hold on where your tipping point is, only difference is your number may be off from the actual number, but for the purposes of gaining/losing it’ll still work.

(KM) #15

Jason Fung, Obesity Code, posits that the body prefers to remain at a weight set-point. This makes it extremely difficult to pinpoint a “deficit” or use that to formulate a meaningful calorie reduction behavior, because the body will aggressively defend the set point, instigating hunger if the calorie intake is too low, or adjusting its caloric burn in response to the calorie intake, either by dropping RMR (a reason people who fast often feel cold, the body is conserving its fuel stores for more important uses) or encouraging more sedentary behavior through feelings of tiredness.

(Chuck) #16

This is so true I have been there way too many times over the last 12 years. I tried the calorie counting method for about 12 years, and I would lose a few pounds and reach a set point and be stuck there and either gain weight or I would try something different and maybe lose to the next set point. I found the most reliable method of convincing my body to lose more weight was to eat more calories for a few weeks and even maybe gaining a pound or two, then slowly reduce calories and see if I could lose a few more pounds. I even changed up my diet by eating low carb and eating high carb, eat lots of protein and or fat. But in the end I would lose the fight to my body. It wasn’t until I got serious about fasting that I have seen the best results. Why? Because the deficit I cause my body is by eating the way my body wants to be fed. I give my body the food it need and desires when it needs and desires it, then I fast cutting off all calories for 19 hours on average. The process for me has been slow, and I have actually learned to be patient, something I haven’t been known for. So to be honest a calorie deficit is necessary for weight loss but your body has to believe it isn’t in a deficit. This is like walking a tightrope until find the correct solution for your body. It means listening to your body, and allow t to determine what and when you eat, and stop listening to TV ads, friends and family that want to feed you. It is saying NO most of the time to food.