Fat Consumption is the Only Cause of Weight Gain

Summary: Researchers say dietary fats, not sugars or proteins, are the only cause of weight gain.

Source: University of Aberdeen.

Scientists from the University of Aberdeen and the Chinese Academy of Sciences have undertaken the largest study of its kind looking at what components of diet – fat, carbohydrates or protein – caused mice to gain weight.

Since food consists of fat, protein and carbs, it has proven difficult to pinpoint exactly what aspect of the typical diet leads to weight gain.

Part of the problem is that it is very difficult to do studies on humans where what they eat is controlled for long enough periods to work out what are the most important factors, however studies on animals that are similar to us can help point in the right direction.

The study was published in the journal Cell Metabolism and includes 30 different diets that vary in their fat, carbohydrate (sugar) and protein contents.

The mice were fed these diets for three months, which is equivalent to nine years in humans. In total over 100,000 measurements were made of body weight changes and their body fat was measured using a micro MRI machine.

Professor John Speakman, who led the study, said: “The result of this enormous study was unequivocal – the only thing that made the mice get fat was eating more fat in their diets.

a monster burger
The mice were fed these diets for three months, which is equivalent to nine years in humans. In total over 100,000 measurements were made of body weight changes and their body fat was measured using a micro MRI machine. NeuroscienceNews.com image is in the public domain.

“Carbohydrates including up to 30% of calories coming from sugar had no effect. Combining sugar with fat had no more impact than fat alone. There was no evidence that low protein (down to 5%) stimulated greater intake, suggesting there is no protein target. These effects of dietary fat seemed to be because uniquely fat in the diet stimulated the reward centres in the brain, stimulating greater intake.

“A clear limitation of this study is that it is based on mice rather than humans. However, mice have lots of similarities to humans in their physiology and metabolism, and we are never going to do studies where the diets of humans are controlled in the same way for such long periods. So the evidence it provides is a good clue to what the effects of different diets are likely to be in humans.”

About this neuroscience research article

Source: Laura Graham – University of Aberdeen
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Dietary Fat, but Not Protein or Carbohydrate, Regulates Energy Intake and Causes Adiposity in Mice” by Sumei Hu, Lu Wang, Dengbao Yang, Li Li, Jacques Togo, Yingga Wu7, Quansheng Liu, Baoguo Li, Min Li, Guanlin Wang, Xueying Zhang, Chaoqun Niu, Jianbo Li, Yanchao Xu, Elspeth Couper, Andrew Whittington-Davies, Mohsen Mazidi, Lijuan Luo, Shengnan Wang, Alex Douglas, and John R. Speakman in Cell Metabolism. Published July 12 2018.

Cite This NeuroscienceNews.com Article

[cbtabs][cbtab title=”MLA”]University of Aberdeen”Fat Consumption is the Only Cause of Weight Gain.” NeuroscienceNews. NeuroscienceNews, 14 July 2018.
<https://neurosciencenews.com/fat-consumption-weight-gain-9573/>.[/cbtab][cbtab title=”APA”]University of Aberdeen(2018, July 14). Fat Consumption is the Only Cause of Weight Gain. NeuroscienceNews. Retrieved July 14, 2018 from https://neurosciencenews.com/fat-consumption-weight-gain-9573/[/cbtab][cbtab title=”Chicago”]University of Aberdeen”Fat Consumption is the Only Cause of Weight Gain.” https://neurosciencenews.com/fat-consumption-weight-gain-9573/ (accessed July 14, 2018).[/cbtab][/cbtabs]


Dietary Fat, but Not Protein or Carbohydrate, Regulates Energy Intake and Causes Adiposity in Mice

•Energy intake was linked only to dietary fat levels and not protein or sucrose
•Adiposity increased with increasing fat content to 60% but thereafter declined
•Hypothalamic hunger pathways were unresponsive to dietary protein content
•Dopamine, opioid, and serotonin pathways were all stimulated by fat intake

The impacts of different macronutrients on body weight regulation remain unresolved, with different studies suggesting increased dietary fat, increased carbohydrates (particularly sugars), or reduced protein may all stimulate overconsumption and drive obesity. We exposed C57BL/6 mice to 29 different diets varying from 8.3% to 80% fat, 10% to 80% carbohydrate, 5% to 30% protein, and 5% to 30% sucrose. Only increased dietary fat content was associated with elevated energy intake and adiposity. This response was associated with increased gene expression in the 5-HT receptors, and the dopamine and opioid signaling pathways in the hypothalamus. We replicated the core findings in four other mouse strains (DBA/2, BALB/c, FVB, and C3H). Mice regulate their food consumption primarily to meet an energy rather than a protein target, but this system can be over-ridden by hedonic factors linked to fat, but not sucrose, consumption.

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  1. There is a large question mark over the quality of the research effort and the analysis of results over this work. Strange how excess sugar or carbs are converted to triglycerides and stored as fat. But according to this work that reality doesn’t happen. Nothing ground breaking here other than possibly poor work.

  2. I think everyone is missing the point. It is not fat that makes the mice fat, it is the fat in their diet making them hungrier, which in turn increases their caloric intake, and that increase in calories makes them fat.

  3. Poor journalism. The study does not show equal calories from fat and carbs causes different fat gain. The study basically shows that if the food tastes better the mice will eat more. What a mouse likes to eat and what a human likes to eat is gonna be very different so your title is crap

      1. Thanks Joe Doe im not neuroscience but all my alarms are trigger when i read this

  4. Did anyone even read the basic abstract? The research only concluded that mice couldn’t auto regulate calorie intake ddu to fat stimulating certain pleasure pathways thereby leading to weight gain. Someone needs to heavily edit this struggl.

  5. The culturally pejorative description of fats as “hedonistic” is unscientific and a serious red flag that this study has a built in bias. How are sweet foods or salty, crispy low-fat Triscuits not hedonistic? The processed food giants must be scared to death that people are losing weight and often becoming healthier by steering clear of their products.
    I would need to see the exact macros (fat/carb/protein proportions) of this study, but as a 58-year-old woman who has tried many diets over 25 years, the well formulated, nutrient dense ketogenic diet is the only diet which suppresses my appetite for many hours, has allowed me to kick food addictions to refined carbohydrates and simple sugars, reduced my BMI to 20-21, and has kept my weight stable within 7 lbs for 2 years. It takes a while for the human body to adjust to the diet, at least 3 weeks but sometimes a couple of months. I wonder what the equivalent time period is in mice.

    1. I have been on a high fat diet (not keto, more like LCHF) for more then 5 years now and I actually struggle to PUT ON weight. Most of the people I know that had switch from normal, high-carb diet to low carb or keto had also lost on weight significantly and also improved on their health conditions. Food cravings are also typical for people on normal/high carb diets, while people on high fat can keep on without eating for even 8 hours, having their dinner at 5 pm after only a bulletproof coffee in the morning…

  6. Were all mice fed fed the exact same number of calories and did they experience the same level of calorie burning? Were they fed at the same time of day? Were their insulin/blood glucose levels monitored throughout?

    In my personal experience it’s impossible to gain weight simply by eating more fat. You have to massively overeat and/or trigger an insulin response which causes the body to story fat instead of burn it for fuel. Genetic factors are of course always at play in individuals, but overeating calories from fat in conjunction with refined sugars triggering an insulin response and then themselves being stored as excess adipose tissue is the classic recipe for weight gain.

    Americans quit eating fat, put themselves into starvation/overeating mode with low calorie/high sugar foods and generally wrecked their own health from the late 1970s til today on the advice of a few scientists working from imperfect, biased data. Sound familiar?

  7. Really? Carbs turning to fat happens in mice. Not in humans ( unless really ovese ) but in mice yes.

    Lyle Mcdonald talked about this in one of his books.

    Anyway no big surprise. In a caloric surplus the fat is stored as fat. Easiest way to be in a caloric surplus? Eat fat and carbs with low protein and fiber.

  8. So it wasn’t a conspiracy by the sugar industry it was the fat after all?
    then how do we account for all those supposedly strictly vegetarian blubbery animals?
    carbs especially refined carbs are turned to sugar which are then in turn turned to fat, triglycerides, cholesterol.
    so let us continue to ingest lot of sugar directly and refined carbohydrates (sugar indirectly) so that we can all lose weight and have a healthier healthspan. Different kinds of sugar have metabolic consequences that are quite different sucrose is not the only kind of sugar we consume. I would have to say that this study is quite limited in scope and that it probably helps some part of the sugar industry to the detriment of us all.
    please see: How the Sugar Industry Shifted Blame to Fat – The New York …

  9. I’m 56. Last year my physician took my Harmon patch away. I was using clamara 0.75 she was also giving me steroids and my weight jumped to 25 pounds. I eat a low calorie and fat diet. I’ve went to another doctor and had my thyroid checked and he prescribed 0.25 Harmon patch. I can’t get my weight down.

  10. At the end of the day, it’s not a human study. Lots of people on YouTube have done their own n=1 experiments with overfeeding themselves on a high fat diet. So far, people either maintain weight, gain slightly, or lose slightly on a high fat, high calorie, diet. Yet I’ve seen vegans who have consumed extremely high carbohydrate diets and end up being skinny. Others have put on tons of weight instead. There’s no definitive answer, yet. But for sure, there seems to be a principle of individuality involved. Certain diets for certain people seem to be effective

  11. The article is misleading and the title misses the point. The fat diet caused more calorie consumption and THAT is what made the mice fat. Basically more intake causes more weight gain. For mice, fats caused more consumption. Many humans consume a gigantic amount of carbs and they do gain weight becasue of it. The title should be “Fat consumption leads to more calorie intake – in mice.”

  12. This is a horrible representation of the study, and is a click bait headline. Fat is not the cause of weight gain. Over consumption is the cause of weight gain, and eating more fat can lead to overconsumption according to the study.

  13. Explain why low carb high fat diets are the craze right now because of the rapid fat loss.

    I don’t think anyone can dispute that people are losing weight when increasing fat and cutting out carbs and sugar. Many of these same people find the weight coming back on when switching back to a diet high in sugar and carbs.

    Makes me question the legitimacy of this study or wonder if we are not similar to mice metabolically.

  14. So I’ve read this article several times over and it’s clearly saying that sugar (or any carb or protein) can never cause weight gain. I personally dont think its so well worded to say that carbs or protein dont cause weight gain cause this has been proven that they do. At a minimum carbs form Glucose stores which cause water retention and protein helps build muscle which also causes weight gain. So maybe it would be better to say it doesnt ever get stored as fat deposits in the body?

    Which leads me to ask, Is this a refutation of lipogenesis? Lipogenesis is a myth? Not asking this to be argumentative, but out of curiosity and thirst for knowledge. I’ve always wondered how and why the body would turn something/anything that doesn’t have fat into fat deposits on the body.

    1. Hi, this is a super complex question you’re wondering about…carbs and protein can cause weight gain in excess just like fat can. Its important to note that all of these forms of energy contain calories, and eating more calories than your body needs is what drives weight gain. Therefore, technically any form of calories (fat, carbs, or protein) could lead to weight gain. (Its also important to remember that some people might be a little more complicated when it comes to weight gain and loss (genetics, etc), but still an important basic thing to keep in mind.)

      Yes, carbs can form “glucose stores,” as you say, but only around 2,500 cals worth (less than 1lb of body fat). Beyond those stores, your body will either store excess calories as muscle or fat, depending on your physical activity level and food intake, to be used during “starvation.” This shows lipogenesis is not a myth, but rather a great thing that our bodies should do to help keep us alive, healthy, and happy!

  15. That’s is ridiculous to say, that fat is the only cause of weight gain. Overconsumption of any macronutrient will lead to weight gain. Under consumption of any of these macros will lead to weight loss. Take the Keto diet for example, a diet highly based on fat.

  16. You did not take into account those who are insulin resistant and so there body and consume facts and not sugars/carbs! Hence that could cause there weight gain and not the fats.

  17. “These effects of dietary fat seemed to be because uniquely fat in the diet stimulated the reward centres in the brain, stimulating greater intake.”

    So they didn’t control for calories?

  18. All the variables and they did not test a ketogenic 75 fat, 20 protein, 5 carb diet. How do you willfully exclude that unless the study has an agenda?

  19. I’m glad there are people with good hearts caring for the well being of the lowly mouse. I did not realize I should not be feeding my pet mouse the discarded pieces of fat from my ribeye steaks. No wonder he’s so plump! Thank you for bringing this to my attention. neurosciencenews.com is now my go-to source for all of my pet health information!

  20. All types of fat, including healthy fats? Avocado, fat in nuts, and olive oil too?

  21. I thought the only way to gain weight was through a higher caloric intake? Did I miss something?

  22. But we DON’T “regulate our food consumption primarily to meet an energy target”, so claiming that fat is the only factor because it overcomes that regulation (which I see no evidence is a major factor for us) is kinda silly.

  23. this study proves nothing other than that mice do not have the same metabolic pathways as humans. lipogenesis de novo and fatty acid synthesis are real and long studied human biochemical metabolic processes that literally use the molecules of glucose and amino acids (carbs and protein respectively ) to produce fat molecules which are stored throughout the body. if you are consuming calories in excess of what you are expending you absolutely will produce fat. the mystery is, what percentage of each macro influences which metabolic processes the most? how do we work with food and exercise to stimulate endocrine and metabolism while minding overal system health? i can say for sure from experience : medium high fat, very low carb, high protein (atkins influenced diet scheme) has allowed me to retain and even grow new muscle , while staying lean ; despite an average 1600 daily calorie intake.

    bottom line : fat gain does NOT occur purely as a result of eating foods containing fat molecules, in fact the opposite can be true

    im wondering if this research summary isnt a tabloid purely on how completely far off it is from current long studied biochem processes.

    if these researchers wanted a disciplined specimen i would have gladly proven the opposite of their results for a small struggling student fee (500 per month)

    fat: 83g (747 cal)
    carbs: 20g (80 cal)
    protein: 180g (720 cal)

    1550 approximate total daily calories
    run 3x fasted or pre fast per week
    weight lift 3x per week
    exercise at above moderate intensity.
    i am 34 y/o male 5′ 9″ 175 with visible vascularity in arms back. abs and thighs. and above average visible muscularity (maybe 12% total body fat. )
    i eat without containment one day per week (saturday) which i have an extra high intensity weightlift session and moderate intensity. (stairstep 10-15 minutes hr @ 160 bpm for 8 – 13 minutes)
    usually a lot of carbohydrate is consumed but calories get up to 3-4k calories. i would cut that out if someone paid me for research.

  24. You can’t correlate weight gain in mice to that of humans because they don’t have the same physiology and they’ve evolved eating very different foods. What a ludicrous study — who paid for it? What a ludicrous article.

    In humans, the link between high insulin levels and weight gain is well established. What raises insulin the most? Refined carbohydrates like fructose. What raises insulin the least? Fat. Let’s not further confuse an already very confused American population.

  25. How can I possibly believe this when I see people becoming whole again on keto? Diabetes is being reversed, arthritis is being put into remission. People are coming off blood pressure medication. We are not mice!

  26. If this is true, how do you explain how people lose weight on the Keto diet which is primarily eating high fat, low carb?

    1. calorie deficits, no matter the source of calorie youre cutting, will result in weight loss in most people.

  27. This arcticle is bunk. It’s calories in. Is you eat 3500 calories of broccoli more than your maintenance, you will gain 1 lbs of fat. I understand what this article is getting at, but it’s vilifying fat. People who don’t think for themselves will see this and just think if they stay away from fats they won’t gain weight. Articles like this shouldn’t exist. Reword it. You should feel ashamed.

  28. Im not a rat and I lost 50 pounds on the keto diet….which is eating mostly healthy fats so I can even start to believe this.

  29. This is absolutely, hilariously wrong. Go ahead kids eat as much sugar and carbs as you want, no weight gain here.

  30. I’d love to know who funded this research. This couldn’t be further from the truth. I know from personal experience

  31. Here we go with everyone going on low fat diets. Since when does a study prove a theory. You got to retest and retest and get the same results. This is why science has become a sham. If, what you say is true, then which fats? Eliminating fat from one’s diet is severely unhealthy. What about Vitamins A,D, and K, which are fat soluble vitamins? I have a really wonderful idea, why don’t we stop worrying about weight gain, and focus on health. The studies showing weight affects health is correlation and correlation is not causation. Why don’t you worry about finding cures for illnesses instead of blaming them on weight? Correlation does not causation. One test does not prove a theory.

  32. I believe it. When I eat a “good” high-fat diet like a ketogenic one, I gain weight the same as if I ate cake and cookies. I’ve tried everything in the world and for me at least, it’s about the calories.

  33. I would say, not in my case. I gained weight not eating fats, a miniscule amount maybe, only ate carbs and sugars. Your study proves only weight gain in mice. I lost weight following a low carb high fat low sugar diet, completely opposite to what you conclude.

  34. This headline is misleading. This is not a fact. It is the interpretation of the results of one experiment.

  35. Does that mean calories don’t matter anymore? Is it just fat we have to worry about?

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