Dieta cetogénica: preguntas y respuestas.

hola

una duda q tengo: no hay ninguna diferencia en uno q meta por ejemplo 30gr de HC en la dieta (5%) q uno q meta solo 14 grHC (2%) metiendo los dos las mismas calorias en la dieta? solo q uno mete algo mas de HC

gracias
 
la maquina de impedancia me marcaba un 42% de agua en cetosis y ahora un 52% se que no son muy de fiar pero pueden orientar,ademas no se suponia que con las cargas se aumentaba hasta 4kilos pero solo era agua?ahora es al reves?

Yo no soy partidario de las 'super-cargas', de vez en cuando hago 'días a base de fruta', pero mi objetivo en los días ricos en CH no es coger 5 kilos. Me parece un estrés innecesario y antinatural. Además, yo no como nada de granos. Mi única fuente de CH es y seguirá siendo la fruta.Porque aunque tengan fructosa, no tienen nada de grasa, y considero que rellenar el glucógeno hepático tiene mayor impacto en el metabolismo que rellenar solo el muscular a base de espaguettis y arroz.

Yo simplemente como para disfrutar, y mi dieta es predominantemente de grasa y productos animales.
pero se supone que si llevas 6 meses en cetosis y no consumes hidratos el cuerpo tiene que tirar de grasa,si no estas en un 3 o 4% de que ha tirado tu cuerpo durante seis meses? o tira de la grasa que ingieres,por lo cual habria que quitarla tambien,no?

Claro, los ácidos grasos que ingieres no 'desaparecen', tienes un concepto muy equivocado de la cetosis entonces. Si comes grasa, ésta se utilizará también como energía, y si hay muchas calorías en exceso, puedes hasta engordar.¿ Qué es lo que hacen el eliminar los carbohidratos? Pues maximizar el uso de grasa como energía, pero la regla de las calorías se sigue cumpliendo (aunque la mayoría de la gente coma a saciedad y engorde menos que con una dieta mixta).


He aprendido mas que en la vida de nutricion en este foro,solo estoy asustado por lo que me queda por aprender aun
saludos

+1[/QUOTE]

pablo osea q tu no comes ni lentejas ni frijoles ni garbanzos ni nada?
 
Ejemplos de ello es que un multivitaminico todos los días a largo plazo disminuye la capacidad del cuerpo para luchar contra los radicales libres. Porque se hace 'dependiente' de las dosis de vitaminas

Ok, gracias por la aclaración. Lo digo porque yo tomo suero de leche, y alguna vez he tomado creatina. Supongo que lo ideal es tomarse un descanso de vez en cuando

Saludos
 
Exactamente, la disminución de la T3 es un mecanismo anti-aging.


Puedes postear exactamente lo que comías?

SUPONgo que te refieres a mi, claro te lo posteo.
ALMUERZO GR KCAL PROT GRSAS HC
bacon 2 lonchas 50 175 8 15 0,6
tortilla 2 huevos 120 232 19 18 0
queso roquefort o brie50 190 11 16 0
aceite oliva 10 90 0 10 0
TOTAL .... 230 687 38 59 0,6
COMIDA
pollo/cerdo/ternera/cordero 150 200 32 11 0
calabacin/esparrago/alcach 100 17 1,2 0 3,6
pimiento/champi
aceite oliva 10 90 0 10 0
TOTAL........... 260 307 33,2 21 3,6
MERIENDA 1
requeson con sacarina 200 216 18 13 7
proteina sabor 20 30 19 0 0
TOTAL............. 220 246 37 13 7
MERIENDA 2 POSTENTRE
queso batido con sacarina 200 216 18 13 7
TOTAL........... 200 216 18 13 7

CENA
pollo/cerdo/ternera/cordero 150 200 32 11 0
calabacin/esparrago/alcach 100 17 1,2 0 3,6
pimiento/champi
aceite oliva 10 90 0 10 0
TOTAL.......... 260 307 33,2 21 3,6

TOTALES 1220 1750 160,4 127 21,8
1750KCaprox reparto nutrientes 35% 60% 5%

se me han descuadrado un poco los numeros al copi/paste pero se entiende,esta es la cetogenica fin de semana cena del sabado libre,mucho arroz integral,pan,carne,judias,helado y un cubata de ron cola light,
domingo libre solo la comida al mediodia,pasta con carne y tomate pan fruta y helado. lunes otra vez al sitio.
A QUE OS MOLA,(ACORDAROS QUE ESTA DIETA TIENE COPIRIGHT JEJEJ)
 
y ahora la psfm

Desayuno: BATIDO PROTEINA DE SUERO O CARBS 30g de proteina

Media mañana: 2 latas de atún + pequeña ensalada 100gr tomate+50cebolla

Almuerzo: 150GR PANGA PLANCHA 70GR CALABACIN


Merienda (PRE entreno): 40g de proteína de suero de leche
40g de proteína

Cena: 150GR PANGA PLANCHA Y 70GR CALABACIN
Para dar sabor se puede añadir vinagre, especias, zumo de limón..
 
Originalmente publicado por Pablo23 Si, pero la de novo lipogenesis (conversión de CH a grasa) es un proceso tan extraño e inexistente que apenas merece mención. La conversión de CH a grasa es tan insignificante y mínima que probablemente no hayas convertido casi ni un gramo en toda tu vida. Hay expertos que dicen que harían falta unos 800 gramos de CH durante unos 3 días para que se conviertan en grasa.
pablo si la lipogenesis es tan rara y complicada cuando comes hidratos de carbono en exceso que pasa con esa energia,se espulsa por la orina?por termogenesis?se evapora por la piel? o se convierte en grasa¿ digamos 100gr de hc de exceso durante 2meses, si la lipogenesis es casi imposible que ocurre con ellos?
pdt:no es que me meta contigo ni tu ciencia,es QUE QUIERO ENTENDERLO
saludos
 
Bueno me prepare una dieta cetogenica leyendo en el foro, es MUY AMATEUR, seguramente tenga varios errores para corregir, sobretodo en los calculos de necesidades, pero bueno, es la primera vez q me preparo una dieta y q me informo sobre los alimentos.... a ver q les parece:

8.30 am: 100gramos de jamon cocido+100gr de queso+25g de mani salado= 484kcal/6.6hc/52prote/28grasa

14.30 pm: 200gr de carne+100gr de ensalada+10gr de aceite de oliva= 570kcal/8hc/41prote/40.2 grasa

17.00 pm (pre-entreno): 25 gr de mani salado= 144kcal/3.1hc/6prote/12grasa
19.00 pm (post-entreno): 100gr jamon, 100gr queso= 340kcal/3.5 hc/ 46prote/ 16grasa
21.30 p.m: 200gr pollo+100gr ensalada+10gr aceite de oliva= 460 kcal/8hc/44prote/30.2 grasa

total= kcal:1998
hc:29.2
prote:189
grasa:126.4

deberia agregar un suplemento proteico despues de entrenar o al desayuno? un multivitaminico por lo q dicen no haria falta no?

los dias en q NO entreno simplemente bajo el tamaño de las porciones?

a partir del dia 13 recien tendria mi primer carga no?


toda ayuda o critica se agradeceee!

un saludo!

me habia olvidado: entreno 4 veces x semana, rutina de fuerza (3/4 años entrenando ya+muchos de deporte)

altura 1.67 peso actual 76kg

objetivo: perder 3-6 kg de grasa
 
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i encuanto a la sal, se debe tomar o no?

La sal importa mucho menos cuando estás en una dieta cetogénica. Puedes darle un toque salado a cada comida.

pablo osea q tu no comes ni lentejas ni frijoles ni garbanzos ni nada?[/QUOTE]

No, cuando desayuno (que no es siempre) me tomo unos huevos con bacon y chorizo asturiano, todo bien frito y grasiento. De almuerzo una ensalada con aguacates, frutos secos o semillas y aceite de oliva con un buen filete de carne o pescado (atún o salmón frescos). Y de cena, parecido al desayuno, normalmente no suelo cenar a menos que haya entrenado ese día. Y muchismas otras recetas que tengo. De hecho, las mejores recetas internacionales son low-carb.
Originalmente publicado por Pablo23 Si, pero la de novo lipogenesis (conversión de CH a grasa) es un proceso tan extraño e inexistente que apenas merece mención. La conversión de CH a grasa es tan insignificante y mínima que probablemente no hayas convertido casi ni un gramo en toda tu vida. Hay expertos que dicen que harían falta unos 800 gramos de CH durante unos 3 días para que se conviertan en grasa.
pablo si la lipogenesis es tan rara y complicada cuando comes hidratos de carbono en exceso que pasa con esa energia,se espulsa por la orina?por termogenesis?se evapora por la piel? o se convierte en grasa¿ digamos 100gr de hc de exceso durante 2meses, si la lipogenesis es casi imposible que ocurre con ellos?
pdt:no es que me meta contigo ni tu ciencia,es QUE QUIERO ENTENDERLO
saludos

Esos carbos irían primero al glucógeno y después preferentemente a ser utilizados por el cuerpo. Cuantos más carbos comes, más carbos quemas. La glucosa es un compuesto tóxico para la sangre y lo único que quiere hacer tu cuerpo con ellos es eliminarlos lo más rápido posible.

Los siguientes factores han demostrado activar la de novo lipogénesis:
-Baja ingesta de grasa en la dieta (-10%).
-Ingesta alta prolongada.

El cuerpo es muy listo. Por ejemplo, cuando faltan grasas saturadas en la dieta, el cerebro empieza a pedirte dulce para convertir inmediatamente esos carbohidratos en grasa saturada.
 
Última edición:
Joder, pablo.. con solo 17 años, no veas si tienes verborrea ! :D

Es muy interesante lo que cuentas y se nota que te encanta todo lo relacionado con la nutrición. Es verdaderamente sorprendente lo que controlas, aparte de que estoy totalmente deacuerdo con lo que dices y lo tengo comprobado.

He leido tu blog y sincceramente, es una información muy interasante. algunas cosas ya las había leido y he seguido ese patrón en varias ocasiones.
Estoy totalmente deacuerdo y de hecho, tengo claro que voy a seguir esas pautas de forma permanente.
Con lo que aún no me atrevo, es con tanta grasa saturada, no solo por un miedo, posiblemente infundado, si no porque me da agonía meterme tanta grasa animal... siento angustia, no sé... a ti no te pasa?


Un saludo y felicidades por tus comentarios...
 
Pablo y en volumen para ganar masa muscular, cuanto seria la cantidad de macronutrientes a utilizar si necesitas muchas kcal? Los ch a menos de 100 para entrar en cetosis y rellenamos todas las demas kcal a base de grasas o una dieta mas equilibrada en cuanto a nutrientes, en definitiva como lo haces tu?

un saludo crack
 
Joder, pablo.. con solo 17 años, no veas si tienes verborrea ! :D

Es muy interesante lo que cuentas y se nota que te encanta todo lo relacionado con la nutrición. Es verdaderamente sorprendente lo que controlas, aparte de que estoy totalmente deacuerdo con lo que dices y lo tengo comprobado.

He leido tu blog y sincceramente, es una información muy interasante. algunas cosas ya las había leido y he seguido ese patrón en varias ocasiones.
Estoy totalmente deacuerdo y de hecho, tengo claro que voy a seguir esas pautas de forma permanente.
Con lo que aún no me atrevo, es con tanta grasa saturada, no solo por un miedo, posiblemente infundado, si no porque me da agonía meterme tanta grasa animal... siento angustia, no sé... a ti no te pasa?


Un saludo y felicidades por tus comentarios...

Entiendes bien el ingles?

Si lo haces, mira este papel del American Journal of Clincal Nutrition

HEALTH EFFECTS OF SATURATED FATTY ACIDS
The approach of many mainstream investigators in studying the effect of consuming saturated fats has been narrowly focused to produce and evaluate evidence in support of the hypothesis that dietary saturated fat elevates LDL cholesterol and thus the risk of CAD. The evidence is not strong, and, overall, dietary intervention by lowering saturated fat intake does not lower the incidence of nonfatal CAD; nor does such dietary intervention lower coronary disease or total mortality (31, 61). Unfortunately, the overwhelming emphasis on the role of saturated fats in the diet and the risk of CAD has distracted investigators from studying any other effects that individual saturated fatty acids may have on the body. If saturated fatty acids were of no value or were harmful to humans, evolution would probably not have established within the mammary gland the means to produce saturated fatty acids—butyric, caproic, caprylic, capric, lauric, myristic, palmitic, and stearic acids—that provide a source of nourishment to ensure the growth, development, and survival of mammalian offspring.

Fatty acids are essential parts of all body tissues, where they are a major part of the phospholipid component of cell membranes. Saturated fatty acids have been suggested to be the preferred fuel for the heart (62). Fatty acids are used as a source of fuel during energy expenditure, and heavy exercise is associated with decreases in the plasma concentrations of all free fatty acids. In light exercise, fat metabolism may be controlled to favor adipose tissue lipolysis and extraction of free fatty acids from the circulation by muscle, whereas in heavy exercise, adipose tissue lipolysis is inhibited and hydrolysis of muscle triacylglycerols may play a more important part (63). In the absence of sufficient dietary fat, the body synthesizes the fatty acids that it needs from carbohydrates. The major fatty acid synthesized de novo via fatty acid synthase is palmitate, which undergoes elongation involving acyl-CoA and malonyl-CoA to form longer-chain saturated fatty acids. Desaturation via fatty acyl-CoA desaturases introduces unsaturation at C4, C5, C6, or C9. The lack of capability to desaturate past C9 makes dietary linoleic acid an essential fatty acid (for review see reference 64). Synthesis of palmitic acid is also increased by consumption of very-low-fat diets with a high ratio of sugar to starch (14).

Based on the controversy over the effects of fat in the diet, the question most often addressed is, What are the relative cholesterolemic effects of the major saturated fatty acids in the diet? However, the evidence suggests that caproic, caprylic, and capric acids are neutral with respect to cholesterol-increasing properties and their ability to modulate LDL metabolism; lauric, myristic, and palmitic acids are approximately equivalent in their cholesterol-increasing potential, and stearic acid appears to be neutral in its cholesterol-increasing potential (65; for review see reference 66). A limited number of controlled studies suggest that myristic acid is the most potent cholesterolemic dietary saturated fatty acid (for review see reference 67). However, there is evidence that the increase in chlolesterol is related to an increase in both LDL and HDL cholesterol (68). Aside from the reported effects on plasma cholesterol concentrations, there are other properties and functions of the individual saturated fatty acids that support beneficial roles in the body. Some of these roles are briefly discussed below.

Butyric acid
Short-chain fatty acids are hydrolyzed preferentially from triacylglycerols and absorbed from the intestine to the portal circulation without resynthesis of triacylglycerols. These fatty acids serve as a ready source of energy, and there is only a low tendency for them to form adipose (69). Butyric acid (4:0) is the shortest saturated fatty acid and is present in ruminant milk fat at 2–5% by weight (70), which on a molar basis is approximately one-third the amount of palmitic acid. Human milk contains a lower percentage (0.4%) of butyric acid. No other common food fat contains this fatty acid.

Butyrate is a well-known modulator of genetic regulation (71, 72), and it also may play a role in cancer prevention (73). Published information thus far indicates that butyric acid exhibits contradictory and paradoxical behavior (74). Although butyric acid is an important energy source for the normal colonic epithelium, is an inducer of the growth of colonic mucosa, and is a modulator of the immune response and inflammation, it also functions as an antitumor agent by inhibiting growth and promoting differentiation and apoptosis (75).

Caproic, caprylic, and capric acids
In bovine and human milk, caproic acid (6:0) is present at 1% and 0.1% of milk fat, respectively, and caprylic acid (8:0) and capric acid (10:0) are present at 0.3% and 1.2% of milk fat, respectively. Goat milk contains the highest percentage of caprylic acid, at 2.7% of milk fat. These 3 fatty acids have similar biological activities. Both caprylic acid and capric acid have antiviral activity, and when formed from capric acid in the animal body, monocaprin has antiviral activity against HIV (76, 77). Caprylic acid has also been reported to have antitumor activity in mice (78). Negative effects of these fatty acids on CAD and cholesterol have not been a dietary issue.

Lauric acid
Lauric acid (12:0) is a medium-chain fatty acid that is present in human and bovine milk at 5.8% and 2.2% of milk fat, respectively. This fatty acid has been recognized for its antiviral (79) and antibacterial (80, 81) functions. Recent results suggest that Helicobacter pylori present in stomach contents (but not necessarily within the mucus barrier) should be rapidly killed by the millimolar concentrations of fatty acids and monoacylglycerols that are produced by preintestinal lipases acting on suitable triacylglycerols, such as those present in milk fat (82). Lauric acid is also effective as an anticaries and antiplaque agent (83). Medium-chain saturated fatty acids and their monoacylglycerol derivatives can have adverse effects on various microorganisms, including bacteria, yeast, fungi, and enveloped viruses, by disrupting the lipid membranes of the organisms and thus inactivating them (84, 85). This deactivation process also occurs in human and bovine milk when fatty acids are added to milk (86, 87). The release of monolaurin from milk lipids by human milk lipases may be involved in the resulting antiprotozoal functions (88, 89). One study indicated that one antimicrobial effect against bacteria is related to the interference of monolaurin with signal transduction or toxin formation (90). In addition to disrupting membranes to inactivate viruses, lauric acid has an effect on virus reproduction by interfering with assembly and maturation, ie, cells make the components of the virus, but their assembly is inhibited (79).

Myristic acid
Bovine milk fat contains 8–14% myristic acid (14:0), and in human milk, myristic acid averages 8.6% of milk fat. As stated above, myristic acid is one of the major saturated fatty acids that have been associated with an increased risk of CAD, and human epidemiologic studies have shown that myristic acid and lauric acid are the saturated fatty acids most strongly related to average serum cholesterol concentrations. However, in healthy subjects, although myristic acid is hypercholesterolemic, it increased both LDL- and HDL-cholesterol concentrations compared with oleic acid (68).

Palmitic acid
Palmitic acid (16:0) is present in human and bovine milk at 22.6% and 26.3% of milk fat, respectively. Palmitic acid in triacylglycerols in human milk is predominantly esterified in the sn-2 position of the molecule. Feeding human infants a formula containing triacylglycerols similar to those in human milk (16% palmitic acid esterified predominantly in the sn-2 position) has significant effects on fatty acid intestinal absorption (91, 92). Myristic, palmitic, and stearic acids are better absorbed from human-like milk than from standard formula, without a change in total fat fecal excretion. Mineral balance is improved in comparison with a conventional formula, as shown by lower fecal calcium excretion, higher urinary calcium, and lower urinary phosphate. The specific distribution of the fatty acids in the triacylglycerol is known to play a key role in lipid digestion and absorption. Because pancreatic lipase selectively hydrolyzes triacylglycerols at the sn-1 and sn-3 positions, free fatty acids and 2-monoacylglyceriols are produced. Free palmitic acid, but not 2-monopalmitin (which is efficiently absorbed), may be lost as a calcium-fatty acid soap in the feces. A comparison between the effects of dietary laurate-myristate and the effects of palmitic acid in normolipemic humans showed that palmitic acid lowers serum cholesterol (93). In humans, replacement of dietary laurate-myristate with palmitate-oleate has a beneficial effect on an important index of thrombogenesis, ie, the ratio of thromboxane to prostacyclin in plasma (94).

Stearic acid
Dietary stearic acid (18:0) is derived primarily from bovine meat and dairy products. Stearic acid is present in human and bovine milk at 7.7% and 13.2% of milk fat, respectively. In relation to the question of their effects on serum cholesterol, stearic acid and saturated fatty acids with <12 carbon atoms are thought not to increase cholesterol concentrations (95). Dietary stearic acid decreases plasma and liver cholesterol concentrations by reducing intestinal cholesterol absorption. Recent data from studies with hamsters, which have a lipoprotein cholesterol response to dietary saturated fat that is similar to that of humans, suggest that reduced cholesterol absorption by dietary stearic acid is due, at least in part, to reduced cholesterol solubility and further suggest that stearic acid may alter the microflora populations that synthesize secondary bile acids (96).

The absorption of stearic acid from triacylglycerols containing only oleate and stearate depends on the position of esterification. 2-Monstearin is well absorbed if the stearic acid is esterified at the sn-2 position of the triacylglycerol. If the triacylglycerol is esterified at the sn-1 or the sn-3 position, it is released as free stearic acid, and in the presence of calcium and magnesium, it is poorly absorbed (97). In a study of the effects of dietary fat on serum lipid and lipoporoteion concentrations, the absorption of dietary oleic acid, palmitic acid, and stearic acid was similar, which indicates that differential effects of these fatty acids on plasma lipoprotein cholesterol are not due to differential absorption (98). Another study in humans also indicated that, even though stearic acid appears to have different metabolic effects with respect to its effect on the risk of cardiovascular disease than do other saturated fatty acids (95), reduced stearic acid absorption does not appear to be responsible for the differences in plasma lipoprotein responses (99).

Compared with consumption of dietary palmitic acid, consumption of dietary stearic acid (19 g/d) for 4 wk by healthy males produced beneficial effects on thrombogenic and atherogenic risk factors (100). Mean platelet volume, coagulation factor VII activity, and plasma lipid concentrations decreased significantly with consumption of the stearic acid diet, whereas platelet aggregation increased significantly with consumption of the palmitic acid diet. A subsequent study showed no alteration in plasma lipids, platelet aggregation, or platelet activation in short-term (3 wk) feeding trials when stearic acid and palmitic acid were provided in commercially available foods (101). An interesting finding in a study of the association between the composition of serum free fatty acids and the risk of a first myocardial infarction was that the percentage content of both very-long-chain n–3 fatty acids and stearic acid is inversely associated with the risk of myocardial infarction. The investigators speculated that the very-long-chain n–3 fatty acids might reflect diet but also that these 2 free fatty acids might in some way be related to the pathogenetic process and not just reflect their content in adipose tissue (102).
 
Exactamente, la disminución de la T3 es un mecanismo anti-aging.

PD: De todas maneras, estos estudios afirman que la caida en la T3 no implica una disminución del metabolismo (1,2)

(1)Phinney S.D. et. al. The human metabolic response to chronic ketosis without caloric
restriction: physical and biochemical adaptations. Metabolism (1983) 32: 757-768.

(2)Acheson KJ and Berger AG. A study of the relationship between thermogenesis and thyroid
hormones. J Clin Endocrin Metab (1980) 51: 84-89.

Hypothyroidism and euthyroid stress syndrome (ESS)
There are two common syndromes associated with low levels of T3 which need to be
differentiated from one another. Hypothyroidism is a disease characterized by higher than
normal thyroid stimulating hormone (TSH) and lower levels of T3 and T4. The symptoms of this
disease include fatigue and a low metabolic rate.
The decrease in T3 due to hypothyroidism must be contrasted to the decrease seen during
dieting or carbohydrate restriction. Low levels of T3 with normal levels of T4 and TSH (as seen in
ketogenic dieting) is known clinically as euthyroid stress syndrome (ESS) and is not associated
with the metabolic derangements seen in hypothyroidism (1). The drop in T3 does not appear to
be linked to a drop in metabolic rate during a ketogenic diet (17,52).

As with other hormones in the body (for example insulin), the decrease in circulating T3
levels may be compensated for by an increase in receptor activity and/or number (1). This has
been shown to occur in mononuclear blood cells but has not been studied in human muscle or fat
cells (53). So while T3 does go down on a ketogenic diet, this does not appear to be the reason for a
decrease in metabolic rate.
 
Última edición:
Entiendes bien el ingles?

Si lo haces, mira este papel del American Journal of Clincal Nutrition

HEALTH EFFECTS OF SATURATED FATTY ACIDS
The approach of many mainstream investigators in studying the effect of consuming saturated fats has been narrowly focused to produce and evaluate evidence in support of the hypothesis that dietary saturated fat elevates LDL cholesterol and thus the risk of CAD. The evidence is not strong, and, overall, dietary intervention by lowering saturated fat intake does not lower the incidence of nonfatal CAD; nor does such dietary intervention lower coronary disease or total mortality (31, 61). Unfortunately, the overwhelming emphasis on the role of saturated fats in the diet and the risk of CAD has distracted investigators from studying any other effects that individual saturated fatty acids may have on the body. If saturated fatty acids were of no value or were harmful to humans, evolution would probably not have established within the mammary gland the means to produce saturated fatty acids—butyric, caproic, caprylic, capric, lauric, myristic, palmitic, and stearic acids—that provide a source of nourishment to ensure the growth, development, and survival of mammalian offspring.

Fatty acids are essential parts of all body tissues, where they are a major part of the phospholipid component of cell membranes. Saturated fatty acids have been suggested to be the preferred fuel for the heart (62). Fatty acids are used as a source of fuel during energy expenditure, and heavy exercise is associated with decreases in the plasma concentrations of all free fatty acids. In light exercise, fat metabolism may be controlled to favor adipose tissue lipolysis and extraction of free fatty acids from the circulation by muscle, whereas in heavy exercise, adipose tissue lipolysis is inhibited and hydrolysis of muscle triacylglycerols may play a more important part (63). In the absence of sufficient dietary fat, the body synthesizes the fatty acids that it needs from carbohydrates. The major fatty acid synthesized de novo via fatty acid synthase is palmitate, which undergoes elongation involving acyl-CoA and malonyl-CoA to form longer-chain saturated fatty acids. Desaturation via fatty acyl-CoA desaturases introduces unsaturation at C4, C5, C6, or C9. The lack of capability to desaturate past C9 makes dietary linoleic acid an essential fatty acid (for review see reference 64). Synthesis of palmitic acid is also increased by consumption of very-low-fat diets with a high ratio of sugar to starch (14).

Based on the controversy over the effects of fat in the diet, the question most often addressed is, What are the relative cholesterolemic effects of the major saturated fatty acids in the diet? However, the evidence suggests that caproic, caprylic, and capric acids are neutral with respect to cholesterol-increasing properties and their ability to modulate LDL metabolism; lauric, myristic, and palmitic acids are approximately equivalent in their cholesterol-increasing potential, and stearic acid appears to be neutral in its cholesterol-increasing potential (65; for review see reference 66). A limited number of controlled studies suggest that myristic acid is the most potent cholesterolemic dietary saturated fatty acid (for review see reference 67). However, there is evidence that the increase in chlolesterol is related to an increase in both LDL and HDL cholesterol (68). Aside from the reported effects on plasma cholesterol concentrations, there are other properties and functions of the individual saturated fatty acids that support beneficial roles in the body. Some of these roles are briefly discussed below.

Butyric acid
Short-chain fatty acids are hydrolyzed preferentially from triacylglycerols and absorbed from the intestine to the portal circulation without resynthesis of triacylglycerols. These fatty acids serve as a ready source of energy, and there is only a low tendency for them to form adipose (69). Butyric acid (4:0) is the shortest saturated fatty acid and is present in ruminant milk fat at 2–5% by weight (70), which on a molar basis is approximately one-third the amount of palmitic acid. Human milk contains a lower percentage (0.4%) of butyric acid. No other common food fat contains this fatty acid.

Butyrate is a well-known modulator of genetic regulation (71, 72), and it also may play a role in cancer prevention (73). Published information thus far indicates that butyric acid exhibits contradictory and paradoxical behavior (74). Although butyric acid is an important energy source for the normal colonic epithelium, is an inducer of the growth of colonic mucosa, and is a modulator of the immune response and inflammation, it also functions as an antitumor agent by inhibiting growth and promoting differentiation and apoptosis (75).

Caproic, caprylic, and capric acids
In bovine and human milk, caproic acid (6:0) is present at 1% and 0.1% of milk fat, respectively, and caprylic acid (8:0) and capric acid (10:0) are present at 0.3% and 1.2% of milk fat, respectively. Goat milk contains the highest percentage of caprylic acid, at 2.7% of milk fat. These 3 fatty acids have similar biological activities. Both caprylic acid and capric acid have antiviral activity, and when formed from capric acid in the animal body, monocaprin has antiviral activity against HIV (76, 77). Caprylic acid has also been reported to have antitumor activity in mice (78). Negative effects of these fatty acids on CAD and cholesterol have not been a dietary issue.

Lauric acid
Lauric acid (12:0) is a medium-chain fatty acid that is present in human and bovine milk at 5.8% and 2.2% of milk fat, respectively. This fatty acid has been recognized for its antiviral (79) and antibacterial (80, 81) functions. Recent results suggest that Helicobacter pylori present in stomach contents (but not necessarily within the mucus barrier) should be rapidly killed by the millimolar concentrations of fatty acids and monoacylglycerols that are produced by preintestinal lipases acting on suitable triacylglycerols, such as those present in milk fat (82). Lauric acid is also effective as an anticaries and antiplaque agent (83). Medium-chain saturated fatty acids and their monoacylglycerol derivatives can have adverse effects on various microorganisms, including bacteria, yeast, fungi, and enveloped viruses, by disrupting the lipid membranes of the organisms and thus inactivating them (84, 85). This deactivation process also occurs in human and bovine milk when fatty acids are added to milk (86, 87). The release of monolaurin from milk lipids by human milk lipases may be involved in the resulting antiprotozoal functions (88, 89). One study indicated that one antimicrobial effect against bacteria is related to the interference of monolaurin with signal transduction or toxin formation (90). In addition to disrupting membranes to inactivate viruses, lauric acid has an effect on virus reproduction by interfering with assembly and maturation, ie, cells make the components of the virus, but their assembly is inhibited (79).

Myristic acid
Bovine milk fat contains 8–14% myristic acid (14:0), and in human milk, myristic acid averages 8.6% of milk fat. As stated above, myristic acid is one of the major saturated fatty acids that have been associated with an increased risk of CAD, and human epidemiologic studies have shown that myristic acid and lauric acid are the saturated fatty acids most strongly related to average serum cholesterol concentrations. However, in healthy subjects, although myristic acid is hypercholesterolemic, it increased both LDL- and HDL-cholesterol concentrations compared with oleic acid (68).

Palmitic acid
Palmitic acid (16:0) is present in human and bovine milk at 22.6% and 26.3% of milk fat, respectively. Palmitic acid in triacylglycerols in human milk is predominantly esterified in the sn-2 position of the molecule. Feeding human infants a formula containing triacylglycerols similar to those in human milk (16% palmitic acid esterified predominantly in the sn-2 position) has significant effects on fatty acid intestinal absorption (91, 92). Myristic, palmitic, and stearic acids are better absorbed from human-like milk than from standard formula, without a change in total fat fecal excretion. Mineral balance is improved in comparison with a conventional formula, as shown by lower fecal calcium excretion, higher urinary calcium, and lower urinary phosphate. The specific distribution of the fatty acids in the triacylglycerol is known to play a key role in lipid digestion and absorption. Because pancreatic lipase selectively hydrolyzes triacylglycerols at the sn-1 and sn-3 positions, free fatty acids and 2-monoacylglyceriols are produced. Free palmitic acid, but not 2-monopalmitin (which is efficiently absorbed), may be lost as a calcium-fatty acid soap in the feces. A comparison between the effects of dietary laurate-myristate and the effects of palmitic acid in normolipemic humans showed that palmitic acid lowers serum cholesterol (93). In humans, replacement of dietary laurate-myristate with palmitate-oleate has a beneficial effect on an important index of thrombogenesis, ie, the ratio of thromboxane to prostacyclin in plasma (94).

Stearic acid
Dietary stearic acid (18:0) is derived primarily from bovine meat and dairy products. Stearic acid is present in human and bovine milk at 7.7% and 13.2% of milk fat, respectively. In relation to the question of their effects on serum cholesterol, stearic acid and saturated fatty acids with <12 carbon atoms are thought not to increase cholesterol concentrations (95). Dietary stearic acid decreases plasma and liver cholesterol concentrations by reducing intestinal cholesterol absorption. Recent data from studies with hamsters, which have a lipoprotein cholesterol response to dietary saturated fat that is similar to that of humans, suggest that reduced cholesterol absorption by dietary stearic acid is due, at least in part, to reduced cholesterol solubility and further suggest that stearic acid may alter the microflora populations that synthesize secondary bile acids (96).

The absorption of stearic acid from triacylglycerols containing only oleate and stearate depends on the position of esterification. 2-Monstearin is well absorbed if the stearic acid is esterified at the sn-2 position of the triacylglycerol. If the triacylglycerol is esterified at the sn-1 or the sn-3 position, it is released as free stearic acid, and in the presence of calcium and magnesium, it is poorly absorbed (97). In a study of the effects of dietary fat on serum lipid and lipoporoteion concentrations, the absorption of dietary oleic acid, palmitic acid, and stearic acid was similar, which indicates that differential effects of these fatty acids on plasma lipoprotein cholesterol are not due to differential absorption (98). Another study in humans also indicated that, even though stearic acid appears to have different metabolic effects with respect to its effect on the risk of cardiovascular disease than do other saturated fatty acids (95), reduced stearic acid absorption does not appear to be responsible for the differences in plasma lipoprotein responses (99).

Compared with consumption of dietary palmitic acid, consumption of dietary stearic acid (19 g/d) for 4 wk by healthy males produced beneficial effects on thrombogenic and atherogenic risk factors (100). Mean platelet volume, coagulation factor VII activity, and plasma lipid concentrations decreased significantly with consumption of the stearic acid diet, whereas platelet aggregation increased significantly with consumption of the palmitic acid diet. A subsequent study showed no alteration in plasma lipids, platelet aggregation, or platelet activation in short-term (3 wk) feeding trials when stearic acid and palmitic acid were provided in commercially available foods (101). An interesting finding in a study of the association between the composition of serum free fatty acids and the risk of a first myocardial infarction was that the percentage content of both very-long-chain n–3 fatty acids and stearic acid is inversely associated with the risk of myocardial infarction. The investigators speculated that the very-long-chain n–3 fatty acids might reflect diet but also that these 2 free fatty acids might in some way be related to the pathogenetic process and not just reflect their content in adipose tissue (102).

MUY BUENO.... GRACIAS PABLO. __genial__
 
Pablo y en volumen para ganar masa muscular, cuanto seria la cantidad de macronutrientes a utilizar si necesitas muchas kcal? Los ch a menos de 100 para entrar en cetosis y rellenamos todas las demas kcal a base de grasas o una dieta mas equilibrada en cuanto a nutrientes, en definitiva como lo haces tu?

un saludo crack

Lee la guía. Saludos!
 
Hace unos dias se lo comenté al amigo Xavi y la verdad que me dejé de preocupar ya por el tema y me voy a centrar en ver resultados y punto pero como tema a discutir y raro es que yo solo meto 240g de proteinas 180g de grasas buenas (aceite de oliva, lecitina de soja, lino, omega 3-6) y de cabos meto ente 10 y 15g diarios y todos procedentes de las verduras...RESULTADO??:

desde el sabado pasado a hoy que me e hecho la ultima comprobacion por curiosidad con las tiras reactivas....de cetosis 0 patateroooo...se mantiene intacta ni coge color (deberia ponerse morada) y llevo 5 dias....la verdad que por experiencia propia cada dia me descoloca mas el tema de la nutricion..mucha teoria mucha teoria pero que pasa con la practica?? ahí lo dejo jajaja

salu2 y gracias a todosss
 
Hace unos dias se lo comenté al amigo Xavi y la verdad que me dejé de preocupar ya por el tema y me voy a centrar en ver resultados y punto pero como tema a discutir y raro es que yo solo meto 240g de proteinas 180g de grasas buenas (aceite de oliva, lecitina de soja, lino, omega 3-6) y de cabos meto ente 10 y 15g diarios y todos procedentes de las verduras...RESULTADO??:

desde el sabado pasado a hoy que me e hecho la ultima comprobacion por curiosidad con las tiras reactivas....de cetosis 0 patateroooo...se mantiene intacta ni coge color (deberia ponerse morada) y llevo 5 dias....la verdad que por experiencia propia cada dia me descoloca mas el tema de la nutricion..mucha teoria mucha teoria pero que pasa con la practica?? ahí lo dejo jajaja

salu2 y gracias a todosss

Que puede que te estés pasando de proteínas. Así de simple. Además, las tiras no siempre funcionan, cetonuria y cetonemia no son lo mismo. Es fisiológicamente imposible que no tengas un leve grado de cetosis.
 
pues mi peso actual es de 85kg (estimo que 7 de grasa) y las cuentas salen 80 x 3g de proteinas = 240 (puse 80 por contar mas o menos lo que es el peso magro)...de hambre 0 de ansiedad 0 de devilidad 0 esque no lo entiendo..una de dos..o estoy acostumbrao a las dietas (mas de 2 años con temas de dietas) o nose jajaja pero vaya..que en mi la cetosis no existe por lo que parece...nose que dirá la bascula...almenos espero ir perdiendo porque si encima ni eso...paque queremos mas!!!!
 
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