Saturated vs Unsaturated Fats for Muscle Growth

Before we proceed to the battle of saturated vs unsaturated fats, let’s recall. Athletes are people for whom overeating is not a bad habit and not part of an unhealthy lifestyle, but a focused event aimed at achieving a specific result – growth in muscle mass. Our physiology is such that for the growth of new muscle mass, the body needs energy beyond what goes to ensure all current costs.

An ideal option for the correct gain of muscle mass would be to provide such a supply of energy that would correspond to the capabilities of the body and no more calories. But it’s practically impossible to calculate this value only in practice.

In vivo, it is unrealistic to establish how much energy the body spends during the day — our activity is always different. It is impossible to predict how much muscle tissue we are able to build at the current moment, taking into account all conditions, although we would like, of course, more.

Therefore, in reality, a strategy often dominates, in which the surplus is pronounced by weight gain. And it is also held due to fat. Then the accumulated fat is removed by diet. Athletes proceed from the premise that it is better to play it safe and gain confidence than to experiment with the minimum necessary surplus and, as a result, gain “a teaspoon a year.”

Since it is necessary to gain fat, in addition to minimizing these mass gains, it will be useful to know that the qualitative characteristics of edible fat during overeating can affect further “cutting,” and the degree of increase in fat reserves.

Saturated vs Unsaturated Fats

Overeating is better with unsaturated fats

Why? Let’s look at the results of one study that compared the effects of overeating with saturated and unsaturated fats. It is worth immediately explaining that all dietary sources of fats contain both saturated and unsaturated fatty acids, but as a rule, some significantly prevail over others.

Within 7 weeks, one group of healthy people was overfed with palm oil (saturated fat), the other with sunflower (unsaturated).

To make it easier to consume these oils, they were added to specially baked muffins, which the participants consumed during the day. The degree of surplus and macros in the diet were the same for all.

So, in summary, the participants increased their body weight approximately equally, but in those who consumed saturated fats, the increase in the amount of fat in the liver and abdominal cavity significantly exceeded that in those who consumed unsaturated, which was accompanied by an increase in the activity of the corresponding genes in the adipose tissue of these areas.

At the same time, in the group of unsaturated fats, the total amount of accumulated fat was slightly less, and the increase in muscle mass was more (almost three times, although the absolute numbers are small).

Scientists came to the conclusion that overfeeding with saturated fats enhances the accumulation of liver and visceral fat, and an excess of energy from unsaturated fats also contributes to an increase in muscle mass.

An increase in visceral fat is associated with a decrease in insulin sensitivity (insulin resistance) since it leads to a decrease in the secretion of adiponectin, which regulates glucose homeostasis.

When overeating, insulin resistance is extremely undesirable, as it leads to an increase in the number of carbohydrates synthesized into fat. And you have to eat a lot of carbohydrates during a mass gain.

We are not talking about deteriorating health.

It turns out that the more fat we gain due to excess saturated fats in the diet, the higher our tendency to subsequent fat accumulation is. – Overfeeding polyunsaturated and saturated fat causes distinct effects on liver and visceral fat accumulation in humans. Rosqvist F, Iggman D, Kullberg J, Cedernaes J, Johansson HE, Larsson A, Johansson L, Ahlström H, Arner P, Dahlman I, Risérus U. Diabetes. 2014 Jul;63(7):2356-68.

But that’s not all for now. Both saturated and unsaturated fatty acids are stored in human adipose tissue. The predominance of one or another type of fatty acid in the diet affects exactly which fatty acids we will stock up on. It is important. Why?

Studies show that the rate of mobilization of fat from fat depots during lipolysis depends on the structure of fatty acids (FA). In the unsaturated, it is the highest. The difference with saturated can reach 6 times. That is, unsaturated are mobilized in the first place. This promises us a less complicated parting with the stores of fat in the body during the cutting period.

Fatty acids are selectively mobilized from human fat cells in accordance with the molecular structure. By modulating the quality of the intake of fatty acids in organs and remodeling the composition of fatty acids in adipose tissue, this selectivity will be relevant for consideration in physiology, healthcare, and epidemiology.

Selective release of human adipocyte fatty acids according to molecular structureThierry RACLOT, Dominique LANGIN, Max LAFONTAN, René GROSCOLASBiochemical JournalJun 15, 1997,324(3)911-915;

Another citation:

The release of individual fatty acids from adipose tissue is selective, which is established by in vitro studies, in vivo, in studies on animals and humans. Typically, fatty acids are more easily mobilized from fat cells when they are short-chain and unsaturated. This selectivity can affect the storage of individual fatty acids in adipose tissue and their subsequent entry into cells (where they are consumed).

The nature of dietary fats can affect lipid homeostasis and body fat deposition. A diet high in Omega-3 polyunsaturated fatty acids (PUFAs) leads to a predominant distribution of absorbed energy toward oxidation rather than storage. Fatty acids are important mediators of gene expression in the liver. Genes encoding both glycolytic and lipogenic enzymes, as well as key metabolic enzymes involved in the oxidation of fatty acids, are regulated by dietary PUFAs.

Selectivity of fatty acids on lipid metabolism and gene expression. Raclot T1, Oudart H. Proc Nutr Soc. 1999 Aug;58(3):633-46

The cited work deals not only with the effect of dietary fats on the composition of fatty acids of adipose tissue but also with their effect on fat metabolism. In particular, omega-3 fatty acids affect the increase in the degree of fat oxidation in the liver, which leads to their greater use as a current source of energy, rather than as a means for deposition.

Monounsaturated also perform well compared to saturated

One study compared whole-body fat oxidation levels in healthy men after breakfast, high in fat (43% of total energy), rich in either monounsaturated fats from olive oil or saturated from cream. 5 hours after breakfast rich in monounsaturated fats, there was a significantly higher rate of fat oxidation and a higher thermal effect of food (energy expenditure on digestion and assimilation) compared to saturated fats.

The authors of the study conclude:

If the level of fat oxidation after eating is higher with the predominance of monounsaturated fatty acids than saturated ones, then a simple change in the type of edible fat consumed can have a positive effect on weight loss in men whose diet consists of a relatively high-fat content.

The influence of the type of dietary fat on postprandial fat oxidation rates: monounsaturated (olive oil) vs saturated fat (cream). Piers LS1, Walker KZ, Stoney RM, Soares MJ, O’Dea K. Int J Obes Relat Metab Disord. 2002 Jun;26(6):814-21

Another later study analyzed various researches that studied diet-induced thermogenesis (DIT, which characterizes energy expenditure on digestion and absorption), energy expenditure (EE), and fat oxidation (FOx) in response to high-fat meals or long-term dietary intervention.

Saturated fats after a single use cause lower DIT and FOx compared to monounsaturated and polyunsaturated fats. This means that the body spends less energy on the absorption of saturated fat, and its involvement in the processes of providing cells with energy after eating is also less pronounced (fat oxidation (FOx) is lower – accumulation is higher).

Long-term dietary interventions also support the belief that unsaturated fats cause larger amounts of EE, DIT, and/or FOx vs saturated fats and that a diet with a high level of monounsaturated fat causes greater weight loss compared to a diet with a high level of saturated fats.

As a conclusion, the authors summarize:

Saturated fats contribute more to fat accumulation than mono- and polyunsaturated fats. Unsaturated fats are more beneficial in terms of metabolism, in particular, monounsaturated ≥ polyunsaturated> saturated, as evidenced by higher DIT and FOx values after meals or high-fat diets.

Effect of dietary fatty acid composition on substrate utilization and body weight maintenance in humans .Krishnan S1, Cooper JA. Eur J Nutr. 2014 Apr;53(3):691-710.

Another study involving healthy women of normal weight between the ages of 18-35 years found that in response to a high-fat meal, diet-induced thermogenesis (DIT) was highest after eating polyunsaturated fatty acids – 10% higher than monounsaturated and saturated. – Acute effect of dietary fatty acid composition on postprandial metabolism in women. Clevenger HC, Kozimor AL, Paton CM, Cooper JA. Exp Physiol. 2014 Sep;99(9):1182-90.

A noticeable metabolic difference is recorded even between monounsaturated and polyunsaturated fats in food. So, in a recent study, the response of healthy men to a 5-day high-fat diet (50% energy from fat) was compared, with the predominance of either mono- or polyunsaturated fatty acids.

At the beginning, the reaction to individual meals was somewhat different from what it was after 5 days of diet. The respiratory coefficient (RER), which describes what type of substrate the cells use to a greater extent, was higher for polyunsaturated fats – which means a lower degree of fat oxidation compared to monounsaturated fats (the higher the RER, the more carbohydrates, and less fat are oxidized and vice versa). And diet-induced thermogenesis (DIT) was lower for polyunsaturated fats.

However, after a 5-day high-fat diet, the change in metabolic reactions in the diet of PUFA was greater, which indicates the metabolic adaptability of a diet rich in PUFA. In particular, the respiratory coefficient of PUFAs became 20% lower than that of monounsaturated ones, that is, the degree of fat oxidation increased (0.08 g versus 0.04 g). – Metabolic responses to high-fat diets rich in MUFA v. PUFA. Polley KR, Miller MK, Johnson M, Vaughan R, Paton CM, Cooper JA. Br J Nutr. 2018 Jul;120(1):13-22.

If you noticed, judging by the two above-mentioned works, the reaction of healthy men and women to high-fat meals with a predominance of poly- or monounsaturated fatty acids is somewhat different. This is recorded in other studies. But the common thing for them is that saturated fats are less beneficial for both of them in terms of consumption/accumulation. This is in healthy ones, but in obese people, the situation is somewhat worse.

Their reaction to different types of fats (subject to a significant amount) is a little different and generally unfavorable. Since obesity in athletes building their body is a rare phenomenon, information on the preference for unsaturated fats in conditions of overeating remains relevant for them. – Metabolic responses to dietary fatty acids in obese women. Clevenger HC, Stevenson JL, Cooper JA. Physiol Behav. 2015 Feb;139:73-9.

The Bottom Line under Saturated vs Unsaturated Fats

During the period of planned overeating, while bulking, it is worth paying attention to the quality of fats used in food. In particular, preference should be given to mono- and polyunsaturated fatty acids.

On the one hand, they are more effectively used as an energy source immediately after their consumption when overeating.

On the other hand, they are more easily mobilized from fat depots during a diet with an energy deficit. Since the intake of one type or another of fatty acids in the diet during overeating affects the composition of human adipose tissue, it is more advantageous for unsaturated fats to accumulate (they are monounsaturated in the human body).

However, do not overestimate the effect of the metabolic reaction of the body on simple manipulations with fats. A pronounced surplus of energy, significantly exceeding the needs of the body in any case, will lead to active fat accumulation. The potential benefits will be noticeable only within a reasonable range of overeating.

Note: Information provided:

• does not indicate that “calories are not equal to calories” – all fats have the same calorie content and it does not disappear anywhere
• clarifies the distribution mechanism of the energy entering the body after consuming one or another type of fatty acid: saturated vs unsaturated fats.

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