Are Diets Lethal For The Brain?

Your Brain, On A Diet

“I’m on a diet.” 

“I’m trying this new fat-free diet.” 

“I’ve been on this diet for 6 months and it’s going great.” 

“I’ve been on this diet for a week and I’m starving.”

“This diet sucks, I’ve not lost a pound.”

“Crikey, I’ve lost 7 pounds in a week with this new coffee diet.” 

We’ve probably all got at least one friend, a family member or a colleague who goes on and on about a diet they’re on or have been on. And sometimes that diet-obsessed person might be us.

Throughout this article we’re going to explore the impact that being on a diet has on the brain. We’re not going to explore the best and worst diets for your cognitive health, instead we’ll focus on the brain’s response to knowing that it’s on a diet. 

And it turns out, being on a diet can do more harm than good and often be a total waste of time and energy. 

Doctor and author Stephen Guyenet’s book, The Hungry Brain, explores why your brain fights diets and it seems that this is thanks to its instinctive, innate desire to encourage you to overeat to maintain an optimum weight. He digs deep into the science behind why we overeat in situations like the following:  

“Have you ever wished you could just stop eating the cake, even as you put another forkful in your mouth? Have you ever wondered why exactly you are still eating chips when you are definitely full?” 

Guyenet says that “body weight is regulated by the brain. If you don’t know that, you’re going to be surprised when your brain and body start fighting back against weight loss.” 

If your mind knows you’re on a restricted diet or trying out a new eating regime, then it may go into a sort of protection-meets-panic mode, to fight against these physical weight loss changes. 

Many authors and scientists agree that being on a diet can in fact make you gain weight. Which seems counter-intuitive. Guyenet explains that your brain has an optimum weight with which it feels satisfied, which could be below the one you want. 

In another of Guyenet’s studies, he highlights the difficulty of fighting the brain’s natural responses to weight loss, with regards to obesity: 

“Although substantial progress has begun to identify neurohumoral mechanisms underlying obesity, nonsurgical obesity treatment has improved little over the years. If obesity involves the biological defense of an elevated level of body fat, as current evidence suggests, advice to simply “eat less, move more” cannot be expected to remedy the problem.

This is because interventions that reduce body fat stores without a corresponding decrease in the defended level of fat mass elicit compensatory responses that promote the recovery of lost fat and are difficult to consciously override… These responses constitute perhaps the single largest obstacle to effective obesity treatment.”

He also goes into detail about how German physician, Bernard Mohr, “first described human obesity associated with abnormalities of the basal hypothalamus more than 170 years ago (Wochenschr. Ges. Heilkunde 6, 565–571; 1840).”  It was in the second half of the century that “a negative feedback loop gradually became evident between the hormone leptin (produced by fat cells) and the hypothalamus, which has turned out to be a crucial regulator of levels of body fat.”

It seems that the involvement of leptin and hypothalamus signalling in obesity is vital to explaining why the brain responds to dieting in the way that it does. If your brain feels like your weight is falling off too quickly, then it may intervene and try to control it.



The study, Dieting and Bingeing: A Causal Analysis, by Polivy and Herman describes how the brain reacts to the idea of dieting negatively. So much so, that it reverts to binge-eating as a form of survival:

“… Dieting usually precedes binge eating chronologically… By supplanting physiological regulatory controls with cognitive controls, dieting makes the dieter vulnerable to disinhibition and consequent overeating.” With other studies similar to this finding “impaired cognitive functioning during spontaneous dieting.”

What’s the answer? How can you lose weight without upsetting your brain’s natural balance and instincts?


Firstly, do your own research. It’s easy to open a newspaper or go online to read up on the latest diet, be it a fad or not. But when you start exploring the actual science-backed research you can access for free online, that’s when you expose yourself to the real evidence-based diet intel.

Secondly, ensure that you’re getting enough quality sleep. Bad sleep has been linked to weight gain in studies such as “Association between Reduced Sleep and Weight Gain in Women” by Patel et al who found that:

“Ultimately, in order to cause weight gain, reduced sleep must increase caloric intake and/or reduce energy expenditure. Short-term sleep restriction lowers levels of the satiety-promoting hormone, leptin, increases levels of the appetite-promoting hormone, ghrelin, and increases subjective ratings on appetite and hunger.” Therefore a solid night’s sleep can help to support your lifestyle choices.

Thirdly, step away from diets and instead create a lifestyle choice of eating habits which are realistic and will sustain you for years to come:

-Choose the right, fresh foods which satisfy your hunger pangs for longer.
– Eat slightly less of what you’ve chosen to eat. 
– Avoid processed foods containing chemicals as these inform your brain to eat more of that product.
– Avoid sugar as it enhances your food cravings.
– Drink more water.
 

Like we said, it turns out that being on a diet can do more harm than good. Instead, focus on eating the right things and introducing an eating plan which you can adhere to (and tweak slightly) for the rest of your life. The result? Your brain may be a little happier.

Sources Cited:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3319208/

https://www.nature.com/articles/493480d

https://psycnet.apa.org/doiLanding?doi=10.1037%2F0003-066X.40.2.193

https://psycnet.apa.org/doiLanding?doi=10.1037%2F0003-066X.40.2.193

https://www.cambridge.org/core/journals/psychological-medicine/article/impaired-cognitive-functioning-during-spontaneous-dieting/047B2389EBB0E325595FC82959C6D153

https://annals.org/aim/fullarticle/717987

https://academic.oup.com/aje/article/164/10/947/162270

Maisie Bygraves

One thought on “Are Diets Lethal For The Brain?

  1. I’d point out that the research shows not all diets are the same. That is why some, such as paleo diet advocates, prefer to call it a lifestyle since the paleo worldview equally focuses on exercise, sleep, relationships, etc. Also, low-carb and zero-carb diets alter the functioning of the body, especially the metabolism and hormonal system.

    On these diets, people find they don’t need to count calories, restrict portions, etc. That is particularly true on the keto diet that changes the appetite causing one to eat less without trying. Many of these low-carb diets go further with emphasizing foods that are nutrient-dense and bioavailable. Some argue it’s more important what you eat than how much you eat.

    What many find with low-carb diets is how easy they are because they tend to improve not only one’s relationship to food but also improve one’s energy, stamina, mood, etc. Low-carb diets have been used in medical practice and clinical studies to effectively treat a wide variety of conditions: epileptic seizures, diabetes, obesity, autoimmune disorders, mood disorders, schizophrenia, etc.

    These aren’t necessarily diets in the normal use of the word. Traditional societies, especially hunter-gatherers, tended to eat lower carb diets. This is the natural eating pattern of humans and hominids for most of evolution, until quite recently.

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