Why Ketogenic Diets Can Sometimes Backfire | Dr. Robert Lustig

« The issue with the ketogenic diet is that you will break it » is the most absurd argument I heard all the time 🤓

Where the fuck you been when I was stuffing bagels and donuts and making myself fat? Now that I am getting near my required weight and becoming healthy, you want to talk about my diet? Get lost !

In ketosis, you make very little insulin, and whatever tiny amount you don’t use gets quickly broken down by the liver and kidneys. Your body doesn’t store unused insulin — it just stops releasing more. – gpt 5.1

I dont trust this guy, i trust ben azadi. Look into what he says as he breaks it down in an easy way to understand about metabolic freedom and health.

This is absolutely nonsense you know I have a lot of respect for this doctor but for him to say what he just said is not true I didn't throw away 4 years of Keto because I broke it once I mean that's nuts to say something like that. It's obvious this doctor is never gone on a ketosis diet with intermittent fasting. I think you should be real careful when saying such things. I can go in and out of keto without issues at all my body is completely fat adopted there's no problems here you can break and go back

Yesss! Very true! It’s no joke. Unfortunately or fortunately as you explained body does its Job perfectly and we get the result & reaction of our own action!
Sometimes we break it to shock our body:))

Come on man.

I believe him. I was on a strict no sugar diet for about 2 month and lost 10 kg from 75kg starting point. Yesterday, I drank a glass of sugar cane juice and I nearly fainted. This keto diet is a cult diet. I'm going back to a balanced diet with plenty of exercise.

My question to all the doctors on keto / carnivore diet talks. If your insulin resistance and you get to your weight goal, is the keto / carnivore a must diet for the rest of your life? Will our bodies ever heal back to a normal function as long as we watch what we eat?.. or are we doomed for life ?

I had to ask ChatGPT

Ketogenic Diet & Insulin Rebound — Explained

You mentioned that insulin might “build up” during keto and then cause fat storage when carbs are reintroduced. Let’s clarify that:

What Actually Happens on Keto:
• Insulin stays consistently low due to minimal carbs
• Your body becomes fat-adapted and insulin-sensitive
• Muscle glycogen is depleted — muscles are “hungry” for carbs

So What Happens When You Eat Carbs After Keto?
• Insulin spikes — that’s normal
• If timed well (e.g. after a workout), insulin shuttles carbs into muscles, not fat
• But: if you overeat carbs + fat in a surplus, insulin can store excess calories in fat cells

The Myth: “Built-up insulin”
• Insulin doesn’t “accumulate” or build up in the body
• But your body’s sensitivity to insulin increases during keto
• So when you eat carbs again, you get a stronger response — more efficient glucose disposal (which is good if muscles are empty)

⸻

⚠️ When Carb Refeeds Go Wrong:
• Too many calories, especially carbs + fats together (e.g. pizza, ice cream)
• Sedentary or high-fat refeed days — no muscle glycogen demand
• Emotional binge instead of planned refeed

In that case, yes: insulin will store excess energy, and some of it will go into fat cells — especially visceral fat if you’re chronically stressed or inflamed.

⸻

✅ How to Refeed the Smart Way
• Time carbs after training (when insulin sensitivity is highest)
• Keep fat intake low on carb days
• Use clean carbs: rice, oats, sweet potatoes, fruit
• Stick to your calorie target

Just take a walk straight after you have you binge.

He used to say it was ok to indulge in a sweet treat say once a week … but make it "a good/worthwhile one" if you do. This seems to contradict that approach.

I'm finding it a bit confusing. Thought the idea was to increase insulin sensitivity so the body would handle carbs/sugar more efficiently…? Is he saying instead, the sensitivity just leads to a spike (when triggered by a meal with carbs) that goes off the chart? Can anyone please clarify?

YEP, hypoglycemic attacks keep me on the straight and narrow xx Doesnt mean I never indulge. It is good to exercise your carb response from time to time. But you have to do it in a measured way. Hypo's have completely curred binge eating compulsion for me. I look at it as a blessing in disguise. 🙂

he speaks from experience

with all due respect, please help me understand overweight drs who dispense diet advice.

Would someone explain what the doctor meant when he said that
"the fat is priming the insulin response"…?
I'm from Italy and do my best to understand.
Thanks

I'd like to see the data backing his opinion. I doubt this "explosion" would happen.

Awwww man! Come on that's gotta not be that bad versus eating carbs all the time!

So you disagree with "this guy." That's ok, but you couldn't carry his jock strap.

Hence, stay away from foods that cause such metabolic mayhem and don't stress the body with such an emergency response. Insulin is its own risk factor, so avoid anything that causes large insulin spikes.

Dr. Ben Bikman explains this…if you're planning a high-carb meal then you should prepare for it by eating a small amount of carbs that day, before that bigger-carb meal…also if you're going to do a glucose test to test for diabetes and are keto/low carb.

Once you are no longer insulin resistant and become metabolically stable, you’ll go right back to ketosis the next day when you resume ketogenic

I give up.

Not sure more clickbaitish the science may be true, but you're not pulling the calories in on one meal to make up for the fat loss you have obtained. It's like saying one slip and you're back to zero; not the case, I know from personal experience. I have more questions than answers on this one.

The insulin is stored as energy in conjunction with the fat. Boosting the fat loss through a well balanced exercise regimen. This guy is full of it.

this guy is full of it.

He is trolling and exaggerating. I have slipped a few times in 6 mos. carnivore and still have lost 70 lbs. and never felt better in my life. At 55 I feel like I am 40 and I bet I will feel even younger once my weight is down to my ideal. Still have 60 lbs. to go.

Nonsense. Only a very limited release of glucose occurs not an explosion 😅😅😅. This guy talks rubbish

Priming the insulin response.Bigger Glucose and bigger insulin explosion in one meal . Thanks again professor Lustig 👍💯🇿🇦

Honestly, one meal will not "undue" your long-term keto diet progress!
I think he is purposely exaggerating to emphasize a valid point.