« Energy balance in general is the ratio between inputs and outputs, the inputs being food and the outputs mainly, but not only, basal metabolism. », introduces Professor Jean-Daniel Lalau, professor of nutrition, former head of the endocrinology-nutrition department at Amiens University Hospital.
He explains this phenomenon with a metaphor: “ Let’s imagine a fireplace: it works more or less well, depending on the quantity and nature of what is given to it (we can give the example of dry wood for starchy foods) on the one hand and the quality of its draft on the other. share, the latter corresponding to what we spend at rest, i.e. the basic metabolism ».
Do I have a low basal metabolism?
Professor Lalau tells us that we are talking about energy expenditure items, metabolism being the most important in quantity (it represents a good half of our expenses). This is what our body spends while resting. This varies greatly depending on the person.
« For a lean mass of 70 kilos, we can have an energy expenditure which varies from simple to almost double (from 1600 to 2500 calories/day)”, explains Professor Lalau. The other items of energy expenditure are physical activity (around a third of expenditure) and expenditure induced by food (around 10% of expenditure).
« The part due to metabolism, however, varies depending on the level of physical activity. indicates Professor Lalau. It is possible to evaluate these energy positions and thus objectify a possible constitutional problem. “ Before that, it is necessary to ensure that there is not an acquired problem, in particular disorders of thyroid function, which are extremely common, especially in women. Indeed, if you have thyroid deficiency, you have a low metabolism and you can therefore gain weight. », Informs the nutrition professor.
The TSH dosage makes it easy to detect. It is also important to be sure that it is not food intake that is to blame, before immediately blaming a low metabolism. You can in fact consume hidden fats or too large quantities of food. “ The quantitative and qualitative dietary survey must be as detailed as possible », Indicates Professor Lalau.
“Some people can “eat whatever they want” without gaining weight, while others have to be very careful”
Once an acquired metabolism problem or dietary deviations are eliminated, it is possible to see if there is a constitutional metabolism problem, by evaluating energy expenditure using direct techniques called calorimetry in a hospital environment.
« In a simpler way, it is possible to approach constitutional metabolism by analyzing body composition, which also provides an evaluation of energy expenditure, by impedancemetry », he adds. “ If we know lean body mass, we can evaluate energy expenditure in relation to », explains our expert.
However, usual impedance scales only examine the lower part of the body and the interpretation of the figure must be done by a nutrition professional. Finally, another way to assess your metabolism if you don’t have these tools is to compare yourself to another person. “ Indeed, some people can “eat whatever they want” without gaining weight, while others must “be very careful” not to gain weight. », Explains the specialist.
If you are found to have a low metabolism (i.e. hypometabolism), “ it is then necessary to play on other expenditure items: increase energy expenditure through physical activity in the event of a sedentary lifestyle and make the most relevant food choices possible on a qualitative level, without restriction however, precisely to properly adjust the level of energy. contribution to recommended physical activity », Informs Professor Jean-Daniel Lalau.
Source: www.topsante.com
