Study finds low-carb diet leads to improved mental wellbeing compared to low-fat one

When people change their diets for what they think is the better, they usually have some aim in mind such as weight loss (the usual one) or improved health and wellbeing. Making dietary changes can, however, involve time and effort, not to mention a sense of sacrifice and/or deprivation. Obviously, for changes to be sustainable, it helps for any downside of a diet to be outweighed by the perceived benefits.

One way the global impact of any change in regime (e.g. dietary, exercise, sleep-related) can be assessed is to measure what is known as the ‘health-related quality of life’ (HRQoL). Specially designed questionnaires are available for this purpose that may encompass both physical and emotional aspects of health and wellbeing.

In a recent study, the HRQoL was assessed in two groups of dieters. One of these was put on a very low carbohydrate diet (think ‘Atkins’). While the other ate a low fat diet. The trial lasted for 24 weeks. Overall, quality of life that related to physical aspects of health improved in both groups, and there was no significant difference between the groups (except for bodily pain, which improved more in the low-fat group).

However, there was a distinct difference between the groups when it came to mental aspects of quality of life: overall, the low-carb group saw benefits here that were not seen in the low-fat group.

The authors of this study speculate on what it is about the low-carb diet that leads to improved mental wellbeing. One possibility here, is that the low-carb diet did not ask individuals to restrict how much they ate. Low carb diets also tend to promote satiety more than low-fat ones. Basically, a low carb diet is less likely to lead to individuals feeling hungry and/or deprived than a low-fat one.

Whatever the precise explanation, though, the most important thing is that from a mental perspective, individuals felt better on the low-carb diet. This has important immediate implications for mental wellbeing. In the long term, though, this benefit of low-carb eating might make this way of eating more sustainable and effective.


Yancy WS Jr, et al. Effects of two weight-loss diets on health-related quality of life. Qual Life Res. 2009 Feb 11. [Epub ahead of print]

14 Responses to Study finds low-carb diet leads to improved mental wellbeing compared to low-fat one

  1. Adam Steer - Better Is Better 17 February 2009 at 1:52 am #

    Interesting addition to the list of low-carb benefits…


  2. Agent 3244 18 February 2009 at 12:20 am #

    Surely, any merit in this study, if it has merit, would lie in the unraveling of the mysteries of the inner workings of the human body. What processes and hormones are food interdependent and effect mood?
    It seems to me that nature intended for our metabolism to be trickle fed. -Carbohydrate would seem to satisfy this need.
    If at some point in our past animal protein swelled our brain, where does that leave us now?

  3. Mary T. 19 February 2009 at 2:14 am #

    I am not surprised that the low carb group faired better, mentally. However, I doubt that the low fat group had less body pain. I am one of many low carbers ( think Atkins ) whose body pain diminished significantly and it had nothing to do with weightloss. I’ve been living this way for over 6 years. Those of us in the low carb/ketogenic community do indeed have a clear view as to why this is such a healthier diet. We are just hoping that the experts catch up.

  4. Jaki 19 February 2009 at 8:32 pm #

    Unfortunately many carbohydrates available are over processed and not natural to us at all. Far from trickle feeding, carbs send blood sugar high which needs pacifying with insulin. It is this which leads to insulin insensitivity and possibly type 2 diabetes.

    It is worth noting that a low carb diet is that. Not a no carb diet.

  5. jake3_14 20 February 2009 at 12:32 pm #

    >It seems to me that nature intended
    >for our metabolism to be trickle fed.
    >Carbohydrate would seem to satisfy this need.

    Prior to the advent of agriculture and animal domestication 10,000 years ago, humanity ate when it could. Hunting parties would eat a light breakfast, and then be on foot most of the day, without much to eat, so that they could stalk prey big enough to be worth the trouble. They ate their main meals in the evenings. Furthermore, paleological and anthropological evidence indicates that hunter-gatherer societies hunted most in the seasons when the local animals were fattest.

    10,000 years is not a long time, compared to the 990,000 homo sapiens existed before. Not only are human beings designed not to be “trickle-fed,” they are adapted to eating animal fat as a primary fuel.

  6. Jackie Bushell 21 February 2009 at 2:21 am #

    I definitely get the ‘ketogenic high’ when I am in ketosis. My perception is that this is an improvement in mood which is more than just the result of escaping the constant hunger pangs I get if I do a low calorie diet.


  7. Trinkwasser 25 February 2009 at 8:37 pm #

    Works for me too, I am mentally much sharper and have more energy when I keep my glucose in range and (presumably) run on ketones. I used to suffer major BG swings several times a day (reactive hypoglycemia) on a low fat high carb diet and these caused major mood swings. I am much more stable on 1/6 the previous dose of venlafaxine and my ADD symptoms are almost non-existent. I seldom reached “truly” diabetic or “truly” hypo blood glucose readings but my BG could go up or down five points or more in an hour, and possibly the changing insulin levels are also a factor. Low carbing keeps all this stuff as even as a “normal” person

  8. Haarajot 27 February 2009 at 2:37 am #

    Since I started low carbing five years ago my mood has improved too. I experience less stress. If I interpret this rightly, this might be caused by more stable blood sugar, lesser insulin levels in my blood and so less adrenalin to correct too high insulin levels.

    I do not know precisely how it works, but I read somewhere (maybe even here) that serotonin levels are boosted by intake of carbohydrates.
    Maybe a more stable level of carbohydrates will result in more stable serotonin levels.

  9. Agent 3244 28 February 2009 at 4:22 pm #

    A valuable comment, Jake and one quite descriptive. Perhaps the scene you describe may have been an event in pre-history.
    I wonder would you transport your imagination back in time and ask of yourself this:-
    Faced with a choice of hunting large mammals or more abundant smaller creatures including mammals, reptiles, and birds, which would you hunt? What are the rewards for energy expended; and what are the risks of death or injury? Young adults would have to be taught and develop the skills required along with some independence. Upon what should they practice?
    If small creatures were worth the effort, as would be the more occasional large mammal, then which skeletal remains are more likely to endure as archaeological finds in modern time?
    Are small kills prized in modern times?
    OK, animal protein has been important to homo-sapiens, but contemporary thinking is that the distinction between man and great apes is some 4mya. In all that time since, and even in times prior, evolution had been shaping our physiology. Upon what was the diet based?
    Ancient and modern evidence supports the theory that calories from protein must not exceed around 40% long term.
    Carbohydrate was important and remains important to present day gatherer-hunters.

    Stalking large prey requires a lot of energy and does not guarantee a kill.. How are you to sustain yourself during the hunt? Butchered and dried meat perhaps. After a couple of strips what would you crave? Some water-rich lush greens I wouldn’t wonder? If you have the knowledge of a truly wild environment then a 24/7 grocery store is all around you. We have lost that knowledge.
    Hunters to this day often prize the blood of the kill. They prize the organs and consume them first. The liver is most highly prized organ and often eaten at the kill site. Find out why and you will find the explanation somewhat insightful.

  10. jake3_14 9 March 2009 at 6:07 am #

    Agent 3244,

    When Lewis and Clark recorded the beauty of America, they learned about “rabbit starvation” from the natives. They knew that the white men would starve themselves on the lean, easily-caught game the explorers’ party favored. Those natives prized the fat from buffalo bone marrow, from which they would make pemmican to sustain them on what they called “the long hunt.” Fortunately, the white men took their cue after going hungry on small game and added a lot of fat to their rations.

    Of course the hunters ate the entire animal, organ meats included — that’s where the vitamins are concentrated. They made use of the bones for broth to get the minerals. Of course they ate carbohydrates. But what they prized was animal fat.

  11. jake3_14 9 March 2009 at 6:11 am #

    The archeological argument is mildly stimulating, but I actually wanted to address the lack of quantifiable health measures reported by the media from this study. How about reporting reductions in triglyceride levels, Apo-B cholesterol, % of body fat, fasting and reactive blood sugar levels, changes in intracellular magnesium and potassium levels, C-reactive Protein, increases in HDL, and other hard measures of health? Is there a link to the study where this data might be found?

  12. Agent 3244 13 March 2009 at 6:46 pm #

    Jake, your point about fat is interesting. I sense your enthusiasm in your words and respect your knowledge of your subject. A recurring theme here on this valuable site is that “links do not necessarily suggest causality” in a similar way my comments here and elsewhere reflect a theme of my own that “knowledge does not necessarily suggest insight” I don’t mean that as a personal affront, rather I feel that the “collective pool of human knowledge” on early 21st century earth is overlooking something. While I continue on my quest to gain knowledge upon the role of dietary fat, past and present and I concede you may be more knowledgeable upon this. Actually, my ultimate goal is simplicity.

    I feel your choice of the ‘rabbit’ as an example is unfortunate as in dietary terms I believe the rabbit is atypical of other small game.
    Lewis and Clark found themselves in an alternate ‘habitat’ and did not possess the knowledge to thrive within that habitat.
    Likewise Johannson, who explored the arctic fringes and studied Inuit? peoples experienced the challenges of living in an alternate habitat. Again a valuable lesson is that you overlook the knowledge of peoples who have learned to thrive in that habit at your peril.

    You began by challenging my comment that;
    >It seems to me that nature intended
    >for our metabolism to be trickle fed.
    >Carbohydrate would seem to satisfy this need.
    There was intended but somewhat obtuse profundity in this comment. I still stand by that. However, in the time that has elapsed I have realised that my assumptions upon which that enigmatic comment was made were slightly flawed and I will have to revisit references to Johannson accordingly.
    You challenge that comment with your enthusiasm for the importance of animal protein within the context of human evolution but unwittingly in your attempts to discredit that comment you lend your support. You stress the significance of fat.
    Fat, I believe has a low glycaemic index and its’ presence slows conversion of carbs to glucose, does it not? Dietary fat in the correct balance is important. My concern with fat is that at 8000+ calories per kilo over-dependency upon calories from fat and or animal protein displaces a lot of calories from less energy dense but more nutrient rich alternate and diverse sources.

    Areas of science have advanced leaps and bounds by recognising the importance of evolutionary theory. We can but hope that such knowledge can be applied insightfully in the quest for human well-being. Human innovation is a marvellous thing; it defines what we are today. On the other hand we concentrate upon our modernity and overlook valuable lessons from the past.

    You referenced 990,000 years of human existence and then latterly propped up your argument with an image of relatively modern peoples boiling broth in pots. In evolutionary terms pots are a relatively recent innovation.

    Humans are pretty smart. However, we run the risk of being seduced into thinking we know it all. Much of what we know is important. ALL of what we don’t know is equally important. Try as hard as I do to acquire new knowledge I find some old stuff gets pushed out and forgotten. That’s as true for me individually as at is for humankind collectively. If we recognised its’ importance knowledge of the past could help us contextualise undertsanding from the present.


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