{"id":29120,"date":"2025-10-25T06:00:44","date_gmt":"2025-10-25T04:00:44","guid":{"rendered":"https:\/\/cristinatomasi.com\/?p=29120"},"modified":"2026-01-07T10:51:52","modified_gmt":"2026-01-07T09:51:52","slug":"calories-lillusion-of-a-number","status":"publish","type":"post","link":"https:\/\/cristinatomasi.com\/en\/calorie-lillusione-di-un-numero\/","title":{"rendered":"Calories: the illusion of a number"},"content":{"rendered":"

For decades we have been told that\u00a0to lose weight just eat fewer calories than you burn<\/strong>.
\n\"Calories in, calories out<\/strong>.<\/em>\"
\nEasy, isn't it?<\/h2>\n

But this equation, simple, reassuring and straightforward, is also\u00a0deeply wrong<\/strong>, if we talk about\u00a0humans<\/strong>\u00a0and not of\u00a0laboratory ovens<\/strong>.<\/p>\n

<\/h3>\n

What is really a calorie?<\/strong><\/h3>\n

A\u00a0calorie<\/strong>, by definition, is the amount of energy required to heat\u00a01 gram of water of 1\u00b0C<\/strong>.
\nIn the food context, we actually use the\u00a0kilocalorie (kcal)<\/strong>, that is, 1,000 calories: the amount of\u00a0heat<\/strong>\u00a0generated when you\u00a0burn<\/strong>\u00a0A food in a calorimeter.<\/p>\n

But the human body is not an oven<\/strong>.
\nIt does not \"burn\" food to generate heat.
\nIt does not measure energy in kilocalories.
\nIt does not convert 100 kcal of sugar and 100 kcal of fat in the same way.
\nE\u00a0never behaves like a linear machine<\/strong>.<\/p>\n

The body does not use heat: it uses ATP<\/strong><\/p>\n

At the cellular level, the\u00a0true biological energy unit<\/strong>\u00a0is not the calorie, but theATP (adenosine triphosphate)<\/strong>.
\nIt is ATP that powers your muscles, your brain, your heartbeat.
\nAnd the production of ATP\u00a0depends on many factors<\/strong>, not just by how many \"calories\" you eat.<\/p>\n

 <\/p>\n

Calories are only potential energy<\/strong><\/h3>\n

Take\u00a0a steak<\/strong>\u00a0or a\u00a0glass of wine<\/strong>: On paper they could have the same caloric content.
\nBut in the body:<\/p>\n

    \n
  • Metabolic pathways change<\/strong><\/li>\n
  • Activated hormones change<\/strong><\/li>\n
  • They change the tissues that will use or store that energy<\/strong><\/li>\n<\/ul>\n

    Wine will raise insulin and overload the liver.
    \nSteak will stimulate glucagon, protein synthesis and thermogenesis.<\/p>\n

    Same number of calories? Yes.
    \nSame biological effect? Absolutely not.<\/strong><\/p>\n

     <\/p>\n

    The myth of energy output<\/strong><\/h3>\n

    \"You burn more than you eat.\"
    \nBut\u00a0how much you burn<\/strong>\u00a0Depends on:<\/p>\n

      \n
    1. The quality and composition of the food<\/strong><\/li>\n
    2. Your hormone profile (cortisol, insulin, androgens, thyroid...)<\/strong><\/li>\n
    3. Your sleep, your sunlight, your body temperature.<\/strong><\/li>\n
    4. Your mitochondrial efficiency<\/strong><\/li>\n
    5. Your digestive and absorptive capacity<\/strong><\/li>\n
    6. Your level of stress, inflammation, disease<\/strong><\/li>\n
    7. The type of movement you do (walking \u2260 sprinting \u2260 weights)<\/strong><\/li>\n<\/ol>\n

       <\/p>\n

      The body\u00a0is not passive<\/strong>. \u00c8\u00a0adaptive<\/strong>.<\/p>\n

      When you eat more, the body may decide to\u00a0spend more<\/strong>\u00a0(more heat, more spontaneous movement, more anabolic hormones).
      \nWhen you eat less, the body can\u00a0slow everything down<\/strong>\u00a0(less thyroid, less heat, less vital drive).
      \nThis is called\u00a0metabolic adaptation<\/strong>.<\/p>\n

       <\/p>\n

      \ud83e\uddec<\/strong> Hormones decide where energy goes<\/strong><\/h3>\n

      Do you want an example?<\/p>\n

        \n
      • In a state\u00a0androgenic<\/strong>\u00a0(high testosterone): calories go toward\u00a0muscles and bones<\/strong>.<\/li>\n
      • In a state\u00a0cortisol<\/strong>\u00a0(chronic stress): the same calories can go toward\u00a0visceral fat<\/strong>, inflammation and\u00a0muscle catabolism<\/strong>.<\/li>\n<\/ul>\n

        \ud83d\udccc Same caloric \"input.\"
        \n\ud83d\udccc\u00a0Opposite metabolic results.<\/strong><\/p>\n

         <\/p>\n

        Interesting data:<\/strong><\/h4>\n

        Two people eating the same amount of calories, with the same macros, can:<\/p>\n

          \n
        • gain or lose weight differently<\/li>\n
        • accumulate fat in different areas<\/li>\n
        • Change their lean mass, insulin sensitivity, mood, thermogenesis<\/li>\n<\/ul>\n

           <\/p>\n

          The body\u00a0doesn't add up the calories like on a calculator<\/strong>.
          \nChallenges\u00a0interprets them, adapts them, directs them<\/strong>.<\/p>\n

           <\/p>\n

          Two people, one pizza - same food, different effects<\/strong><\/h3>\n

          Imagine two people:<\/p>\n

            \n
          • same height<\/li>\n
          • same weight<\/li>\n
          • same number of calories consumed in the day<\/li>\n
          • same pizza on the plate<\/li>\n<\/ul>\n

            But with one important difference:\u00a0the physiological context<\/strong>:<\/p>\n

            \ud83d\udd39\u00a0Person A<\/strong>\u00a0has a\u00a0healthy metabolism<\/strong>:<\/p>\n

              \n
            • High testosterone<\/li>\n
            • Thyroid hormones in balance<\/li>\n
            • Low cortisol<\/li>\n
            • Active muscle mass<\/li>\n
            • Excellent insulin sensitivity<\/li>\n
            • Deep sleep<\/li>\n
            • Mitochondria functioning as nuclear power plants<\/li>\n<\/ul>\n

               <\/p>\n

              \ud83d\udd39\u00a0Person B<\/strong>, on the other hand, is in an altered metabolic state:<\/p>\n

                \n
              • Low Testosterone<\/li>\n
              • Slowed thyroid<\/li>\n
              • Chronically high cortisol<\/li>\n
              • Systemic inflammation<\/li>\n
              • Unstable blood glucose<\/li>\n
              • Little sleep, little sunlight<\/li>\n
              • Lazy, stressed mitochondria<\/li>\n<\/ul>\n

                 <\/p>\n

                Person A probably<\/strong>:<\/p>\n

                \u2705 will use that pizza to replenish muscle glycogen
                \n\u2705 will stimulate an anabolic spike
                \n\u2705 will burn the meal quickly due to active lean mass
                \n\u2705 will be back in balance in a few hours<\/p>\n

                 <\/p>\n

                Person B<\/strong>, on the other hand, could:<\/p>\n

                  \n
                • cause a more pronounced glycemic surge<\/li>\n
                • Stimulate more insulin to compensate<\/li>\n
                • promote the accumulation of visceral fat<\/li>\n
                • Increase drowsiness, subsequent hunger or inflammation<\/li>\n<\/ul>\n

                   <\/p>\n

                  The point is not to demonize food<\/strong><\/h3>\n

                  The pizza itself,\u00a0Is not \"good\" or \"bad\"<\/strong>.
                  \nBut the way in which it is\u00a0assimilated, managed and addressed<\/strong>\u00a0depends on\u00a0who eats it<\/strong>\u00a0and in\u00a0what metabolic state is found<\/strong>.<\/p>\n

                  The body does not receive food as an abstract datum. It interprets it.<\/strong>
                  \nAnd it does this through the filter of your hormonal, digestive, inflammatory, mitochondrial and nervous state.<\/p>\n

                   <\/p>\n

                  The truth?<\/strong><\/h3>\n

                  Calories in, calories out<\/strong>\u00a0is like saying that\u00a0the efficiency of a car depends only on how much gasoline goes in and how much comes out<\/strong>\u00a0- ignoring\u00a0the engine<\/strong>,\u00a0the type of fuel<\/strong>,\u00a0the oil<\/strong>,\u00a0road conditions<\/strong>, e\u00a0the driver<\/strong>.<\/p>\n

                  It is a simplification useful only for nutrition labels and databases.
                  \nNot to really understand\u00a0how the human body works<\/strong>.<\/p>\n

                   <\/p>\n

                  What really matters?<\/strong><\/h3>\n

                  If you want to manage energy, metabolism and body composition, look beyond the numbers:<\/p>\n

                    \n
                  • The\u00a0quality<\/strong>\u00a0food<\/li>\n
                  • The\u00a0type of nutrients<\/strong>\u00a0(protein \u2260 carbohydrates \u2260 fat)<\/li>\n
                  • The\u00a0timing<\/strong>\u00a0(eating at midnight \u2260 eating breakfast)<\/li>\n
                  • Your\u00a0hormones<\/strong>, your\u00a0sleep<\/strong>, your\u00a0circadian rhythm<\/strong><\/li>\n
                  • Your\u00a0mitochondrial resilience<\/strong><\/li>\n<\/ul>\n

                    Calories are only\u00a0one of many variables<\/strong>. And not the most important one.<\/p>\n

                     <\/p>\n

                    Conclusion: yes, the deficit works - but at what price?<\/strong><\/h3>\n

                    For the avoidance of doubt, it is only fair to state this clearly:<\/p>\n

                    If a person introduces\u00a0less energy<\/strong>\u00a0Than it consumes,
                    \nthe body will be\u00a0forced to draw on its reserves<\/strong> (body fat, but also muscle).<\/p>\n

                    \ud83d\udcc9 This means that.\u00a0Slimming down is possible even in a dysfunctional metabolic state<\/strong>.
                    \nBut at what cost?<\/p>\n

                    \ud83d\udd34<\/strong> Yes, the unoptimized person will be able to lose weight....<\/strong><\/p>\n

                    But the price to pay will be high. Much higher than it seems.<\/strong><\/p>\n

                    In the process:<\/p>\n

                      \n
                    • will be more and more\u00a0tired<\/strong>, plus\u00a0hungry<\/strong>, plus\u00a0irritable<\/strong><\/li>\n
                    • sleep will get worse, the\u00a0thermogenesis will drop<\/strong>, will begin to feel\u00a0constant cold<\/strong><\/li>\n
                    • the\u00a0concentration<\/strong>\u00a0Will decrease, the mood will drop<\/li>\n
                    • will disappear the\u00a0motivation<\/strong>, the desire to\u00a0move<\/strong>, of\u00a0socialize<\/strong>, of\u00a0live energetically<\/strong><\/li>\n<\/ul>\n

                       <\/p>\n

                      And the longer it goes on, the more the body will slow everything down:\u00a0metabolism, hormones, energy, desire<\/strong>.
                      \nIt will be a forced march against nature.<\/p>\n

                      He will lose weight, yes,\u00a0But that weight won't just be fat<\/strong>: it will also be\u00a0muscle mass<\/strong> And in some cases,\u00a0more muscle than fat<\/strong>, especially if\u00a0does not train<\/strong> And does not consume enough protein.<\/p>\n

                       <\/p>\n

                      Then what?<\/strong><\/h3>\n

                      Once he reaches \"target weight\"- (assuming he hasn't given up before)<\/em> - will suffice\u00a0resume eating normally<\/strong>\u00a0To see:<\/p>\n

                        \n
                      • the\u00a0weight rise quickly<\/strong><\/li>\n
                      • the body accumulate\u00a0fatter than before<\/strong><\/li>\n
                      • hunger become\u00a0more intense and uncontrollable<\/strong><\/li>\n
                      • the signs of\u00a0satiety completely out of whack<\/strong><\/li>\n<\/ul>\n

                        The brain, deprived for a long time, reacts with\u00a0compulsiveness<\/strong> and it's like\u00a0could no longer stop<\/strong>. And very often it fails.<\/p>\n

                         <\/p>\n

                        \ud83d\udfe2<\/strong> The \"optimized\" person, on the other hand...<\/strong><\/p>\n

                        Even with a\u00a0moderate energy deficit<\/strong>, will be able to:<\/p>\n

                          \n
                        • \u2705 losing\u00a0mainly fat<\/strong>, saving the muscles<\/li>\n
                        • \u2705 maintain energy, mental clarity, vitality<\/li>\n
                        • \u2705 sleep better, regulate appetite, retain motivation<\/li>\n
                        • \u2705 react well to a return to a normocaloric diet,\u00a0recharging the tissues<\/strong>\u00a0instead of fattening<\/li>\n<\/ul>\n

                          It is a qualitative difference, not only quantitative<\/strong>.<\/p>\n

                           <\/p>\n

                          In summary?<\/strong><\/h3>\n

                          Yes, it is possible to lose weight by \"flagellating\" yourself through restriction, starvation and discipline.
                          \nBut it is an uphill path, which the body\u00a0lives as a stress<\/strong>, not as an evolution.<\/p>\n

                          A person can also lose 30 pounds by willpower alone, but if he loses\u00a0muscles, energy and hormonal health<\/strong>, then he just won a battle against the scale,\u00a0non-organic<\/strong>.<\/p>\n

                          The real goal is not\u00a0lose weight at all costs<\/strong>, but to create a body that\u00a0function so well that you can lose weight easily<\/strong>, almost without thinking about it, and then\u00a0no longer resume<\/strong>\u00a0What he let go.<\/p>\n

                           <\/p>\n

                          The real goal is to be well<\/strong> And that is what I wish for you as well.<\/p>\n

                          Love,<\/p>\n

                          Oliver<\/strong><\/p>\n

                           <\/p>\n

                           <\/p>","protected":false},"excerpt":{"rendered":"

                          Per decenni ci hanno detto che\u00a0per dimagrire basta mangiare meno calorie di quante se ne bruciano. \u201cCalories in, calories out.\u201d Facile, no? Ma questa equazione, semplice, rassicurante e lineare, \u00e8 anche\u00a0profondamente sbagliata, se parliamo di\u00a0esseri umani\u00a0e non di\u00a0forni da laboratorio. Cos\u2019\u00e8 davvero una caloria? Una\u00a0caloria, per definizione, \u00e8 la quantit\u00e0 di energia necessaria a riscaldare\u00a01 […]<\/p>\n","protected":false},"author":7,"featured_media":29121,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[178,106],"tags":[184],"class_list":["post-29120","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-benessere","category-alimentazione","tag-calorie"],"_links":{"self":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts\/29120","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/comments?post=29120"}],"version-history":[{"count":0,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/posts\/29120\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/media\/29121"}],"wp:attachment":[{"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/media?parent=29120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/categories?post=29120"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cristinatomasi.com\/en\/wp-json\/wp\/v2\/tags?post=29120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}