{"id":216335,"date":"2026-01-04T13:12:16","date_gmt":"2026-01-04T13:12:16","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/216335\/"},"modified":"2026-01-04T13:12:16","modified_gmt":"2026-01-04T13:12:16","slug":"why-eat-less-move-more-wont-work-for-weight-loss-according-to-experts","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/216335\/","title":{"rendered":"Why \u2018eat less, move more\u2019 won\u2019t work for weight loss, according to experts"},"content":{"rendered":"

It will be no surprise that weight loss<\/a> is one of the most common exercise<\/a> goals on the planet, especially at this time of year. But if losing belly fat is one of your resolutions and you think that exercise<\/a> is the key, then it\u2019s time to think again. <\/p>\n

\u201cThe single best thing we can do for ourselves is exercising. It works on almost all diseases we can measure \u2013 but not for weight loss,\u201d says Professor Christoffer Clemmensen<\/a> of the University of Copenhagen\u2019s Novo Nordisk Foundation Centre for Basic Metabolic Research. <\/p>\n

In fact, studies have repeatedly shown the \u201ceat less; move more\u201d mantra parroted to those looking to lose body fat<\/a> is ineffective. And nor is willpower the vital key that many people believe it to be. <\/p>\n

\u201cWeight loss is not a matter of willpower,\u201d adds his colleague, PhD fellow Valdemar Brimnes Ingemann Johansen. \u201cIt\u2019s critical to acknowledge the powerful biological mechanisms that interact with your environment. <\/p>\n

\u201cGenetic predisposition is a big determinant of our body size and how we look \u2013 and this powerful biology that underlies our body size is often beyond an individual\u2019s control.\u201d <\/p>\n

The pair are responsible for a recent literature review, published in the Cell<\/a> journal, which dives deep into this topic. Here, they reveal more about the lesser-known mechanisms behind weight loss that might just help you achieve your goals this year. <\/p>\n

The problem with a calorie deficit <\/p>\n

A calorie is a unit of energy \u2013 more specifically, one kilocalorie is the estimated amount of energy needed to heat 1kg of water by 1C. Since the 19th century, this has been the most common unit of measurement used for listing energy in food and drink. <\/p>\n

A calorie deficit is the common denominator behind weight loss, and so it is widely prescribed to people looking to lose body fat, presenting the idea that if you expend more calories than you consume, you will create a negative energy balance and lose weight. This fact is not disputed by our experts.<\/p>\n

\u201cAnyone can lose weight if you put them in a restrictive environment,\u201d says Professor Clemmensen. \u201cIt\u2019s the laws of thermodynamics and it will work on everyone; if you have a negative energy balance, you will lose weight. <\/p>\n

\u201cBut you can\u2019t tell people to stay in a negative energy balance in the free world, because you have these strong biological forces that are telling people to eat. Unless you can restrict your meal size, or you have someone to put a lock on your cabinets, it\u2019s just impossible.<\/p>\n

\u201cCalorie deficit comments disregard the power of biology underlying weight control. It\u2019s like telling people who are stressed to relax, or telling people who have psychological illnesses to just get their act together.\u201d<\/p>\n

Read more: What foods nutrition experts really eat to stop chronic illness in old age (and always avoid)<\/a><\/p>\n

\"A<\/p>\n

open image in gallery<\/p>\n

A calorie deficit will cause you to lose weight, but studies suggest the results do not last long-term (Getty\/iStock)<\/p>\n

The new science behind weight loss <\/p>\n

Obesity is classified as a chronic, relapsing disease by the World Health Organisation<\/a>, with the institution reporting: \u201cIn 2021, higher-than-optimal BMI caused an estimated 3.7 million deaths from noncommunicable diseases such as cardiovascular diseases, diabetes, cancers, neurological disorders, chronic respiratory diseases and digestive disorders.\u201d<\/p>\n

So why would our bodies contain \u201cstrong biological forces\u201d to promote or protect a condition linked to ill health<\/a>? The answer, according to Johansen, lies with our predecessors. <\/p>\n

Stored fat would have helped our human ancestors stave off starvation when food was scarce, so the body \u201cremembers\u201d it and tries to replenish these stores when food becomes available, he says. As part of this, the body treats weight loss like a threat, fighting it by releasing a flood of hunger hormones and heightening food cravings while reducing our energy expenditure. <\/p>\n

Historically, this might have been helpful; in the 21st century, where energy-dense foods are more accessible than ever and movement is optional, these impulses can be harmful.<\/p>\n

Professor Clemmensen led a 2025 literature review on this topic, which found evidence to support the presence of what he describes as an \u201cobesity memory\u201d. <\/p>\n

\u201cThis idea about memory of obesity is a little bit elusive,” he says. \u201cWe don\u2019t know where that memory is stored, but you can see it\u2019s there. If you look at studies where people have undergone extreme weight loss, most of them will find their way back quite accurately to their original weight. <\/p>\n

\u201cThere seems to be a very specific memory, for want of a better term, of what your weight was. That\u2019s what we\u2019re working on in our lab to try to understand.\u201d<\/p>\n

The role of this memory will, as with most things in the human body, vary from person to person depending on factors such as genetics.<\/p>\n

\u201cHow much people are able to sustain lost body fat and how they will respond to different types of interventions \u2013 both behavioural and pharmacological, like weight loss drugs \u2013 will depend on the person,\u201d Johansen explains. \u201cWe see quite some variability among people when we look at big clinical trials.<\/p>\n

\u201cIt would be interesting, and very valuable, if we could understand more about what makes one person regain all their lost bodyweight in just a couple of months, while another person is able to sustain their weight loss for years. This is probably, if I am allowed to speculate, down to the interaction between the environment that person is living in and their genetic make-up.\u201d<\/p>\n

Read more: Is the rise of endurance sports a harmless health kick \u2013 or dangerous addiction to adventure?<\/a><\/p>\n

\"Someone\u2019s<\/p>\n

open image in gallery<\/p>\n

Someone\u2019s ability to achieve and sustain weight loss, as well as their response to various interventions such as weight loss drugs and diets, will depend on individual factors such as genetics (Getty\/iStock)<\/p>\n

What actually works for weight loss? <\/p>\n

Anyone who has tried to lose weight will be aware of a disconnect between wanting to reduce body fat and succeeding in doing so. Professor Clemmensen\u2019s idea of \u201cobesity memory\u201d provides a possible explanation for this. <\/p>\n

However, if \u201ceat less; move more\u201d does not work as an approach, what does? This is a tricky question to answer, Professor Clemmensen says, as research into the topic is ongoing.<\/p>\n

\u201cDo we actually have enough knowledge to guide people on how to live, in terms of losing weight? I don\u2019t think so. I think that\u2019s part of the hard truth we, as researchers, sometimes have to deliver,\u201d he says. <\/p>\n

This does not mean diet<\/a> and exercise are unimportant \u2013 wider health-promoting behaviours, regardless of their impact on body weight, should always be encouraged. Eating a nourishing diet rich in a large variety of vegetables combined with protein and some kind of fish is more likely to have a favourable impact on the body \u2013 compositionally and hormonally \u2013 than less nutrient-dense alternatives like junk food, helping you feel and function better. <\/p>\n

\u201cMacronutrient composition will have different effects on the various hormonal systems in the body,\u201d Professor Clemmensen explains. \u201cIf you get all your calories from liquid sugar versus from chicken breast, it will have very different impacts on the hormonal environment in the body, and subsequent feelings of hunger.\u201d<\/p>\n

The same applies for exercise. Moving more will have a transformative effect on health markers such as blood pressure and your risk of chronic diseases, but Professor Clemmensen says, \u201cThere is very little evidence to suggest it can override that memory of prior bodyweight.\u201d<\/p>\n

There is no single intervention that provides an all-encompassing solution, and people\u2019s varied genetic make-ups render blanket prescriptions impossible. But a combination of manageable interventions appears to be the most productive course of action. <\/p>\n

Developing sustainable habits such as sufficient sleep, a nutritious diet and regular exercise will form part of the puzzle. These are things you can implement to improve overall health \u2013 and possibly assist in appetite regulation, energy balance and weight management too. <\/p>\n

But Professor Clemmensen and Johansen suggest that environmental and societal changes, long-term planning and pharmacological interventions are also necessary in reversing wider obesity rates in the long run. <\/p>\n

Read more: From back pain to heart health \u2013 Experts reveal how to counter the negative effects of too much sitting down<\/a><\/p>\n

\"Sufficient<\/p>\n

open image in gallery<\/p>\n

Sufficient sleep quantity and quality can help with appetite regulation (Getty\/iStock)<\/p>\n

The obesity solution<\/p>\n

\u201cTo reduce obesity rates, we have to look at a more long-term perspective, thinking about generations beyond our little existence,\u201d says Professor Clemmensen. \u201cI think we need to funnel a lot of research into preventative strategies and learning how to create societies where we will have fewer gene-environment interactions that lead to obesity in the first place.\u201d<\/p>\n

In other words, the world needs to change to encourage healthier behaviours \u2013 for example, greater prominence and availability of nourishing foods over ultra-processed energy-dense alternatives, and neighbourhoods that prioritise walking and cycling over travelling by car. <\/p>\n

What about weight loss drugs like Ozempic, Wegovy and Mounjaro, which fall under the banner of \u201cpharmacological interventions\u201d?<\/p>\n

\u201cI think weight loss drugs have actually helped people acknowledge how difficult it is to sustain weight loss through willpower,\u201d Professor Clemmensen continues. \u201cNow we have pharmacological tools that we know work, and they will be relevant for people who are made sick by their excess body fat.\u201d <\/p>\n

Yet, as Johansen points out, many of these weight loss drugs \u201cdon\u2019t seem to be good at maintaining weight loss when people stop the treatment\u201d.<\/p>\n

\u201cPeople also experience comorbidities like diabetes, high blood pressure and systemic inflammation when they stop the treatment,\u201d he adds.<\/p>\n

\u201cSome evidence suggests that a combination of exercise and pharmacological weight loss can be very beneficial for supporting weight loss maintenance.\u201d<\/p>\n

Professor Clemmensen also emphasises the importance of promoting healthy behaviours in children \u2013 particularly those aged seven and below, due to their more \u201cmalleable weight regulation system\u201d. <\/p>\n

\u201cThere are different critical periods of your life,\u201d Professor Clemmensen says. \u201cThere\u2019s your time in the womb, then post-birth, then there\u2019s this growth spurt between four and seven \u2013 then again, as a teenager.<\/p>\n

\u201cThere is some genetic predisposition [to changes in weight], but if you put that person or those genes in an environment that is really unsuitable, you risk developing excess fat mass in those critical periods. <\/p>\n

\u201cIt\u2019s not about restricting these children or individuals, but creating an environment in which they don\u2019t have free access to a ton of calories 24\/7, or exposure to a lot of screens, poor sleep and poor psychological health.\u201d<\/p>\n

This could mean reducing the marketing of junk food to children, investing in healthier school meals, standardising restaurant portion sizes and encouraging regular exercise. <\/p>\n

Developing favourable traits in childhood to suit the genetic hand someone has been dealt could then set them on a trajectory to having less body fat as an adult, Professor Clemmensen ventures. <\/p>\n

But his ultimate goal, and the intervention he believes has the greatest scope for success, is researching, identifying and altering an individual\u2019s \u201cobesity memory\u201d. <\/p>\n

\u201cWe still think if we can understand where and how this memory resides, maybe we can erase it and help people reset their body weight,\u201d he says. \u201cIf we can learn to understand the physiology, we can learn how to intervene.\u201d<\/p>\n

Read more: Longevity expert says this diet is more effective than Ozempic at changing the human body<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"It will be no surprise that weight loss is one of the most common exercise goals on the…\n","protected":false},"author":2,"featured_media":216336,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37],"tags":[565,134,111,139,69],"class_list":{"0":"post-216335","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-fitness","8":"tag-fitness","9":"tag-health","10":"tag-new-zealand","11":"tag-newzealand","12":"tag-nz"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/216335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=216335"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/216335\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/216336"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=216335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=216335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=216335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}