Scientists from University of California, Riverside are studying how the popular keto and intermittent fasting diets work on a molecular level, and whether both sexes benefit from them equally.
The idea behind the keto diet is that low levels of carbohydrates and very high levels of fat and protein will force the body to use fat as fuel, resulting in weight loss. Legions of people swear by it, and innumerable companies produce foods designed for those people.
Intermittent fasting operates on a similar principle, restricting eating to a small window of time during the day. During the hours without food, the body exhausts its stores of sugar and switches to burning fat. The fat gets converted to ketone bodies that the brain can use as fuel.
Despite their popularity, scientists have not yet identified the genes or proteins that enable the diets to work — if they work at all.
“The metabolic switch between sugar and fat — it’s amazing that we don’t understand it yet. But if we do, we can tell you if keto is right for you,” said UCR biochemist Sarah Radi.
A new, $2 million grant from the National Institutes of Health will allow Radi and cell biology professor Frances Sladek to investigate that switch. They believe they already have a sense of how it might work.
The key is likely a protein called HNF4 found at high levels in the liver. It is a transcription factor, which converts DNA into RNA, which is then made into new proteins, and it comes in two forms, P1 or P2.
The UCR-led team originally investigated P2 as a pro-cancer protein. They didn’t find a link to cancer, but they did notice mice with high levels of P2 in their livers also had different genes for metabolism.
They also learned that P2 shows up in greater quantity later in the day, which could explain why mice didn’t gain nearly as much weight if the time they eat was restricted — even if the mice ate too much.
Radi suspects an energy-sensing enzyme could cause the switch between P1 and P2, which could then enable the process of burning fat for energy. “That’s what we’re trying to prove,” she said.
Special attention will be paid in this study to the ways male and female mice respond to the keto and intermittent fasting diets. Some research suggests there are differences.
“Keto doesn’t appear to work as well for women, because we metabolize fat differently and have different genes turned on and off in response to fasting,” Sladek said. “But we really do not know why that is nor how it happens — that is what we are hoping to learn.”
Whether the diet is effective for any sex, the researchers caution against taking any diet to an extreme. It’s not clear whether all of the fat gets metabolized on a keto or fasting diet, or whether a lot of it just accumulates in the body. Standard Japanese diets contain 20% fat, American diets average 35%, and keto diets can contain up to 70 or 80%, which is likely an unsustainably high amount.
“If you eat a lot of fat, it will eventually make you fat. If you eat too much of anything it will make you fat — including carrots,” Sladek said. “Ultimately, the most important thing is the amount you eat, what you eat, and the time of day that you eat.”
“If you eat a lot of fat, it will eventually make you fat. If you eat too much of anything it will make you fat — including carrots,” Sladek said. “Ultimately, the most important thing is the amount you eat, what you eat, and the time of day that you eat.” Clearly this ‘scientist’ does not understand the body and how nutrition works. If a ate carrots every day – even in excess, and little else, I would definitely NOT get fat. The combination of carbohydrates and lipids signals the body to STORE fat as triggered by the high levels of insulin. I’d encourage Sladek to do his homework.
That article had nothing to do with intermittent fasting, why did you even mention it?
I’m 63 & female. I do intermittent fasting and keto and it’s working just fine.
I agree with the other comments. It’s insulin spike that signals the body to store fat. Mostly sugar is changed into fat. Whoever wrote the article dose not understand the basic metabolic biology. It’s the carbohydrates that are absobed easily. Fats are difficult to digest. Don’t forget our ancestors hardly ate any carbohydrates in the caves.
OMG…how can these people acquire millions in grants and have so little knowledge as that? I believe eating too much fat would give you massive diarrhea…then you’d stop eating it….long before you’d get fat.
What an idiot!
How refreshing to see the people in the comments section understand metabolism and how sad to see those researchers who are pigeonholed and can’t see the forest for the trees!
Woooooow, they give out the title of “scientists” to just about anybody now days…
Yes, I agree that to many carrots could make you fat- they are high in carbs!
BS article with 100% payed research.
Clearly scientists either didn’t mean what they wrote OR don’t understand how basic pathways work.
This article is completely misleading and being a woman who has recovered her health and lost 100 pounds doing nothing but keto I refute everything here in as uninformed opinion not fact.
Such a load of bull. Keto works better than anything. If you eat too much fat your body will excrete the excess as ketones in the urine. It’s really impossible to eat too much fat because it’s so satiating. I eat far less food in general on keto and intermittent fasting because I’m simply not hungry. Carbs make me extremely hungry. I tried standard CICO diet for months and lost a few pounds could not budge below a certain weight and was constantly tempted by junk food. My weight just yo-yoed constantly. So I went back to keto which I successfully did for 3 years. Immediately dropped 5 pounds and slowly getting lower week by week. I should be at my first goal within 8 weeks.
Fat does not make you fat. Grains & sugar do. Think about fattening up livestock.you feed them grains.
Clearly the writer knows nothing about keto. #1 NOT high protein! (Moderate, which means stays the same.) #2 fat doesn’t make you fat unless you trigger insulin to store it. This is what happens to people who fail at keto, they listen to articles that tell them things like watermelon are ok. Or keto breads. They are not keto, they are a marketing lie. Our bodies were designed for ketosis, it works perfectly for male or female.
This article is the biggest load of garbage. Bad sources left the writer very confused.
The comments below are spot on, the author has a grave misunderstanding of metabolism… A human couldn’t eat enough fat to get “fat” as appetite control would stop it. You don’t “force” the body to ketosis, you let it go back to that after it is “forced” to burn a little but mostly stow excess blood sugar as fat (suffering inflammation and damaged glycocalyx in the meantime) because high blood sugar is toxic – that’s why we have such a rapid, effective and too often grossly overstressed mechanism to deal with excess blood sugar, unfortunately it brings undesirable consequences.. I hope the researchers are better informed..
Quite obvious this person doesn’t have a clue!! True Keto is not high fat and carrots will not make you fat!! Rethink your career sir. Keto has been working for me for 4 years now. Thank you!!!
I lost 100 pounds in 7 months eating low carb, high fat diet. So, eating fat does not necessarily make a person fat of they are restricting carbs and sugars.
You wanna know what is accurate….these comments. This article is not. I have done the keto/low carb/ fasting lifestyle and you what I seen…results!
I started keto/ intermittent fasting and it works just fine for me my memory is better no more inflammation in my knee and a host of other benefits
Dr took me from low carb my sugar went back up crazy and blood work went crazy, I decided to go back to low carb my numbers are perfect now…so I’ll be relying on my own body’s experience.
Bimbos. I am a woman, nearly 50 yrs and do keto and intermittent fasting. Bravo to both.
Been keto/IF for about 16 months ha eost 85 pounds…I’m female over 60
Bob, you obviously did not read the article because it did speak on intermittent fasting. Before you rudely say snide comments…maybe know your facts!
The author is a moron. Should be fired for his stupidity.
Keto doesn’t have anything to do with “very high levels of fat and protein.” I stopped there, as this was yet another ignorant take on keto. People tend to increase fat to replace energy that would have been carbohydrates, which doesn’t mean they have to load up on fat. In fact, the idea is to burn your own fat. Secondly, there’s nothing at all “high protein” about a ketogenic diet. The correct amount of protein is the same correct amount of protein under any diet.
As for not being able to get fat on fat, you definitely can. The point of the keto diet is being able to burn fat again after having destroyed one’s metabolism. This requires giving the cell’s mitochondria a break from excess glucose for an extended time, in which new mitochondria can replace the damaged ones. That doesn’t mean you can party on more energy than you consume. Your body will store extra energy as fat, regardless of whether it comes from fat. Nevertheless, some carbs should be replaced with healthy fats to avoid too high an energy deficit, which will decrease the metabolism, causing other issues.
I’m a 60 year old woman. Last year I lost 95lbs in 11 months, combining low carb with IF and being ‘mindful’ of calories. It worked like a dream after years of failure. Even when eating a keto diet on its own, I hit a plateau I couldn’t seem to get past. It was the combination that made the difference.
Carrots have high carbohydrate content, thus not recommended on a Keto diet.
Lots of intelligent commenters! I started a standard low fat,low sugar, high fiber diet last February. By June I lost about 45 lbs.,but it was a constant struggle. Then I read about Keto. I have done Keto and intermittent fasting ever since. It is way easier – once you’ve gotten a few days in – because I’m almost never hungry and I can’t snack, so I’m far less focused on food. I feel amazing with so much energy. I just reached my first big goal-100 lbs. lost. I have 30 or 40 more to go.Even if they find reason to discredit Keto, I know I’m eating healthier than I ever have, so c’est la vie! God bless you!
Keto is the best I’ve tried! And I won’t settle for anything else now. This article is really given nothing but an empty page and a whole waste of money on research. Im so glad to see the comment section popping with so much more wisdom n awareness compared to this article’s so called Researchers.
Whomever wrote this is absolutely anti-science. You can’t extrapolate that far outside the bounds of your experiment. You have zero clue what you’re talking about and you should feel bad you wrote this garbage.
First of all the person who wrote this article and the researchers, don’t understand how the body metabolizes protein, fat or energy.Yes women and men do differently on Keto and Intermittent fasting. But the lifestyle change itself works. Fat doesn’t make you fat ( no evidence shows or proves it). Unless you’re eating additional carbs or triggering those insulin responses that created the weight gain in the first place. Talk to reputable people and doctors who actually know what Ketogenic diet really is. Im sure half the people in this comment section could educate you on this subject
zero credibility with this article.
Lol people who knew more than scientists from their armchairs and have not done tons of research. You got Pinky and the Brain.
I love how all the keto people came here to suck each other’s egos. I think they were merely stating the “calories in vs calories out” rule of thinking. Meaning that (stomach size availability aside) that you can actually gain weight by consuming just carrots because the reduced calories the object of any diet, no matter how you package it. It you can eat 5,000 calories of carrots a day but only burn 2,000 you would actually gain weight. Not because of lipids or insulin or anything else, just purely because of over consumption. Why does keto or IF work? Because high carb foods are overly palatable and are easy to over consume. Spikes in insulin increase our urge to eats these foods and keep us coming back for more. #dontdieontheketohill
Healthy keto is good fats meaning no seed oils or processed. Keto is moderate protein with low glycemic veggies which works great
Nothing in the article about how carbs don’t satisfy hunger the way fat does. So many excellent, intelligent responses from people out in the real world who have successfully improved their health with keto and intermittent fasting!
This article is embarrassing. Intermittent fasting and healthy ketogenic its simply amazing.
I’m a 59 year old woman. Have been on Keto without fasting for over a year & have lost 50lbs. No other diet plan has ever worked.
Why did the heading on this suggest there was something better for women yet there was nothing about anything better in the article. That is really misleading.
At the age of 73 in Florida I have found a
remnant of good, honest, intelligent
people in the comment section of this
magazine. As your comments imply, the
people who control the sources of
information don’t necessarily have the
same characteristics. In the USA this has
become a universal problem. The people
who control the various competing
spheres of influence in the US-politics,
economics, media, religion, etc are smart
and dedicated to the cause they serve.
Unfortunately they usually don’t want
the audience to know what the cause
The US has become a libertarian society.
Basically that means that “everyone does
what is right in his own eyes”. Unlimited
personal freedom with no personal
responsibility or concern for the common
good. The right-wingers are very “liberal”
or “progressive” about expanding the
rights and freedoms of rich people and
corporations. The left-wingers are
“progressive” about social causes such as
having sex with crocodiles or marrying
your mother. But neither party is trying to
“conserve” the nuclear family (preferably
Christian and married) physically,
spiritually, and economically as the
primary autonomous unit of society-not as
a political hostage of weird social causes
in the Democratic Party , the lifestyles of
the rich and famous in the Republican
Party, not as property of government
programs that are designed and
intended to replace normal parental
responsibilities, and not as property of
mind-controlling and manipulative
corporations with horrible television
commercials. (Does anybody remember
the “twilight struggle” between godless
crummynism and American crapitalism?)
End of rant. Sorry to bother you. I
could write much more if I had a laptop
and knew how to use it. This may be my
first public rant. It looks like we have
turned into bizarroworld and we have
I am female, 63 years old and have lived the keto lifestyle for 7 years. From 238 pounds to 130 pounds in the first six months and have maintained my weight loss without feeling hungry or deprived. I don’t know where these “scientists” received their training but it’s obvious they are talking about something they have never tried. I have “studied” keto for 7 years, I’ll take the $2M grant, thanks!
As soon as I saw NIH, I saw huge red flags..gee I wonder why!
I lost so much weight on keto I had to add back in some more fruits and vegetables that are not as low carb to maintain my weight. I was chubby but malnourished (lost 18 Pounds) when I started Keto for health reasons to help with healing my brain, liver and bowels. I had Irritable bowel with diarreah which healed in the 3 months I did keto. Along with curcumin, purified fish oil and a good low carb liquid multivitamin and I haven’t had symptoms return. It definitely works for weight loss as I was eating huge amounts of calories of the allowed foods. I was not able to do intermittent fasting due to becoming so thin after doing the diet for only a month. You would think these scientists would try it themselves to study it. Perhaps they are more interested in sounding scientific to other researchers than in doing personal research and researching testimonials.
Great interesting read and very informative.
This article needs to be deleted immediately lol. Even Harvard University recently did a study where they were surprised that high saturated fat diets led to better blood biomarkers than those on vegan and other diets. I lost 60 pounds on keto and carnivore with literally zero exercise and I feel better than I ever have. I watch everything from Dr.Ken Berry which is how I started and I follow many other keto and carnivore diet influencers, inckuding women who got off their vegan diets to go keto and carnivore, and everyone is doing great. These idiots saying eating lots of fat will make you fat haha…dumb. There is the old tried and true idea of “too much if a good thing is bad”…but thats different. I love how doctors and scientists love to play God and literally dont understand how so much of our biology works, and yet they preach. Thats not hard science…thats guessing, hypothesis, sudo-epidemiology and assumptions. Keto works. In some RARE cases it might not work due to other medical conditions.
These comments are hilarious. Very angry keto fans.
How does the keto diet work for people who have no thyroid ? Would this help to loose weight?