Outside the nutritional aspects, it might be wise to increase the physical activity and thus the energy flux of an individual when possible to maintain diet-induced weight loss in the long-term. Among some of these strategies we can highlight increasing protein needs, opting for high-fiber foods or programming controlled diet-refeeds, and diet-breaks over a large weight loss phase. Nutritional strategies and dietetic tools are thus necessary to confront these so-called adaptations to weight loss. This review will provide insight into some of the theoretical models for the etiology of metabolic adaptation as well as a quick look into the physiological and endocrine mechanisms that underlie it. This phenomenon has been referred to as 'metabolic adaptation' many times in the literature and plays a very relevant role in the management of obesity and human body weight. One of the main reasons why this tends to happen relies on our body's biological drive to regain the weight we lose to survive. The specific form of each of the four adiabatic ensembles and its heat function and corresponding entropy are listed in Table 1 (see ).Īs the scientific literature has continuously shown, weight loss attempts don`t always follow a linear fashion nor always go as expected even when the intervention is calculated with precise tools. The adiabatic class has the heat function as its thermal equilibrium variable. A collection of systems existing in the various possible microstates, but characterized by the same macroscopic variables, is called an ensemble. For each fixed value of these macroscopic variables (macrostates), there are many possible microscopic configurations (microstates). Ī system in thermodynamic equilibrium with its surroundings can be described using three macroscopic variables corresponding to the thermal, mechanical, and chemical equilibrium. According to the second law of thermodynamics, the entropy of an isolated system never decreases such a system will spontaneously proceed towards thermodynamic equilibrium, the configuration with maximum entropy. This eventually leads to the second law of thermodynamics and the definition of another state variable called entropy.Įntropy is a measure of the number of specific ways in which a thermodynamic system may be arranged, commonly understood as a measure of disorder. However, experience indicates that only certain states occur. The first law of thermodynamics allows for many possible states of a system to exist. This law is sometimes taken as the definition of internal energy and also introduces an additional state variable, enthalpy. The first law of thermodynamics relates the various forms of kinetic and potential energy in a system to the work, which a system can perform, and to the transfer of heat. For example, kinetic energy-the energy that an object possesses when it moves-is converted to heat energy when a driver presses the brakes on the car to slow it down. The first law of thermodynamics states that the total energy of a system remains constant, even if it is converted from one form to another. The heat functions and specific heats are computed using the “unphysical” temperature and expressed in terms of the logarithmic Lambert function. The derivative, integral, Taylor series, approximation formula, and branches of the function are obtained. Thus, a force does work when it results in movement.A generalization of the Lambert function called the logarithmic Lambert function is introduced and is found to be a solution to the thermostatistics of the three-parameter entropy of classical ideal gas in adiabatic ensembles. Using Integration to Calculate the Work Done by Variable ForcesĪ force is said to do work when it acts on a body so that there is a displacement of the point of application in the direction of the force. force: A physical quantity that denotes ability to push, pull, twist or accelerate a body, which is measured in a unit dimensioned in mass × distance/time² (ML/T²): SI: newton (N) CGS: dyne (dyn).No work is done if the object does not move. work: A measure of energy expended in moving an object most commonly, force times displacement.The SI unit of work is the joule non- SI units of work include the erg, the foot-pound, the foot-poundal, the kilowatt hour, the litre-atmosphere, and the horsepower-hour.Integration approach can be used both to calculate work done by a variable force and work done by a constant force.The work done by a constant force of magnitude F on a point that moves a displacement d in the direction of the force is the product: W = Fd.
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