Eric Helms is a pro natural bodybuilder, raw powerlifter and a coach at 3D Muscle Journey. He is based in Auckland, New Zealand.
If you ask someone in the bodybuilding community ‘why do we need fat in our diet?’ the immediate answer is invariably ‘for hormone function.’ At least, that’s always what I hear. But I started to question whether or not it was true because I was always hearing it but I saw almost nothing in the research about it. We basically only have a couple studies that relate fat intake in a direct way to testosterone production[1,2]. Then I started thinking deeper. In a natural athlete in a normal physiological range, is testosterone level indicative of your muscle mass? Maybe. Maybe not. Maybe it’s more about training age.
Why age matters
If you look at the WNBF Worlds or the IFPA Yorton Cup, the top level natural bodybuilding competitions, how old are the average competitors at that level? Typically, they are 35-40 years old. Leroy Perry, who I believe just turned 51, placed second to the monstrous Martin Daniels in the heavyweight division at the WNBF world championships in 2009 in his mid-40s. When you look at him he looks like he’s 32 (and this is just one of many examples).
I guarantee you that the testosterone levels of these guys in their 40s taking top honors at the world level are half of what they were when they were 25, yet their physiques are better today. When you think about it, it makes sense because many of these guys started lifting as teens. That’s 20 to 30 years of lifting under their belts. Talk about time under tension!
Your training age is much more indicative of what your physique will look like compared to having testosterone levels in the high normal to low normal ranges. In the context of a contest preparation diet, the idea that the goal is to manipulate hormones via diet is flawed at the onset. Your hormones are going to do what they do, but nutritionally you should be focusing on what you need to do to get shredded and maintain your resistance training performance.
Fat: a new paradigm
This is why we need to change our paradigm of thinking here. You need to realise that protein intake does not only impact muscle growth. Fat intake does not only impact testosterone. Carb intake does not only impact energy. They all have a lot of functions in the body. If you get locked into one paradigm of thinking you’re going to make conclusions based on incorrect assumptions, and you’ll do things with your training and nutrition that in the end just don’t make sense.
So let’s put fat into context. It’s the dominant fuel as your intensity decreases. It is stored sub-cutaneous and intra-muscular. That’s why sometimes when you’re doing a great job of burning fat, you look small when you diet because the fat in your muscle goes down.
Big fat-burning zone lies
What exactly do we mean when we talk about fat being the dominant fuel as your intensity decreases? This phenomenon makes people in the fitness industry do some whacky stuff. You go into the gym and you look at the cardio equipment and you see the fat-burning zone that tells you to do some really wussy cardio.
Let’s take that even further. If slow cardio is ideal because it is burning 60% of fuel from fat, how do we burn 100%? Because according to this line of logic that would be the true fat-loss key, right? Well, here’s my fat-burning cardio routine for you. I want you to lie on the floor and stay still. You can almost feel yourself getting shredded.
I’m only kidding, of course, but it illustrates the point that the fat-burning zone is one of those big misapplications because the optimum way to improve your body composition is not necessarily about what you’re burning right now. It’s about are you leaner in six months’ time? If you burned a whole bunch of carbohydrates at 5pm and you’re thinking, ‘well, that was a waste of time’, what do you think you’re going to burn for the rest of the day if there’s less carbohydrates available? Other stuff, including body fat[4-6].
Focus on energy, not just fat
The reality is that we use all of the substrates to various degrees all the time. It’s a constantly flowing process across a continuum, it is not an on-and-off switch; something is always getting burned. And if we’re doing the things to maintain our muscle mass and we’re expending enough calories, by the end of our diet we’re going to get leaner.
Now that’s the simple version, but macronutrient intake does have an impact as well. A reduction in dietary fat does appear to impact hormone function[1,2]. But when you dig into the research it’s hard to determine whether that’s the result of a lowered calorie intake[7,8] or what happens to a person as they go on a low-calorie intake over time and get leaner. Then as we really start to dig and get more specific about what we’re talking about and we look at people dieting for drug-free bodybuilding, we start to see even more evidence that perhaps it has a lot more to do with your total energy availability[10,11] than it does with your fat intake.
The truth about T
Think about it. I had someone tell me that if you go under 50g of fat per day you’re done: there goes all of your testosterone. So you’re telling me that when I have 10lbs of extra body fat on me versus 45g calories of fat in my diet, it’s the 45g of fat that’s going to hurt my hormone levels? Not the 10lbs (the 35,000 calories) of fat that’s on my body? We actually already know this from looking at female athletes and the loss of the menstrual cycle. They did the research and they asked, why is this happening? And it turned out that it’s about energy availability, which is a combination of body fat and how many calories you’re eating – not just one small component of that, your dietary fat intake.
So, now we understand that it isn’t quite correct to say that your fat intake has a large direct impact on your testosterone levels. And we also see that the reduction of testosterone levels while dieting is predominantly because of prolonged calorie restriction and lowered body-fat levels rather than macronutrient intake.
Does testosterone matter?
But before we delve further into a discussion on macronutrients and their relationship with testosterone, should we even be focusing on testosterone levels as an important variable during drug-free contest preparation? The underlying assumption of why we even care about testosterone is because it supposedly has some effect on lean mass retention during a diet. However, there was a study of drug-free bodybuilders dieting for competition and despite their testosterone levels decreasing, testosterone didn’t appear to have a relationship with lean body mass loss.
In fact, the hormones that did appear to have a relationship with lean body mass loss were insulin and IGF1, which are actually more affected by carbohydrates intake than fat intake10. Indeed, the researchers suggested that a potential avenue to prevent lean losses would be to try to maintain a higher carbohydrate intake; fat intake wasn’t on their radar.
The take home is that normal physiological ranges of testosterone don’t make huge impacts on muscle mass. Sure, if you have clinically very low levels of testosterone, or if you are taking anabolic steroids, that will have a very visible impact on muscle mass. However, falling from high normal or normal to low normal is an expected occurrence during an extended diet to reduce body-fat levels and is not indicative of how much muscle mass is lost or retained.
How low should you go?
I would say that you don’t want to go too low with your fat intake. The range that I typically recommend for anaerobic athletes such as bodybuilders while dieting is a fat intake constituting somewhere between 15-35% of total calorie intake. I’d say that this intake is probably a good range for about 60%, maybe 70% of people. There is a great degree of individual variability in the response to macronutrient ratios[13,14], and you can and should individualise your diet. Start with this range and then modify the intake if needed based on how things go.
I do have some clients who at times are on lower fat intakes than that, and I do have some on a high-fat, low-carb diet. There are always folks that stray pretty far from the norm, and if you coach a lot of people you need to be prepared for that. As a final note, I’m talking about people who are getting lean for a contest, so they have the nutritional demands of a strength athlete and also a dieter. For someone who is an obese general population client, there may be an argument for higher fat intake if it induces satiety or helps them with consistency. For folks in this camp, we aren’t splitting hairs. They aren’t going to ever find themselves in a situation where they need to do legs in the morning and HIIT at night on 1,800 calories. For them, it’s just about finding strategies to avoid overeating long term and adapting new habits.
A low point
I do think in most cases there should be a ‘don’t go there’ zone but I have gone below 15% of calories with some people. Normally when I consider going low in fat, I sit down with the client and I tell them what I’m thinking about doing with their diet and why. I tell them what I’ve noticed from observation. Perhaps I have seen that when their carbs go too low they tank, training becomes crappy and they feel terrible, and thus we need to cut from somewhere besides carbs. If we are already at the low end threshold for fat intake, and they tell me they’re doing okay, that’s when I’ll consider going even lower.
Often this happens when I’m at the point where I don’t want to add more cardio to their schedule and their protein is already as low as I think we can get away with. Also, because I have the luxury of working with a team of coaches, I bring in the rest of the coaches to this discussion. I might say to them, ‘here’s why I do want to do it, here’s why I don’t want to do it. I think the cost benefit ratio is this, what do you think? Are you okay with it?’ If they give me the thumbs up and the client is fully aware of the pros and cons of the decision, then we make that collaborative choice.
Why a range makes sense
To recap, I’ve given you the range you want to fall between. This makes sense for most people but not all. As an aside, I like to determine fat and carbohydrates as a percentage of calories rather than grams per kg, which I use to set protein. Why is that? It’s because when you’re dieting, you have to be in a deficit. It means that you have a budget. There’s a maximal amount of food you can eat before you’re just not dieting for your show anymore because you’re not in a deficit.
Also, we have a calorie max that we have to be under so something has to be scaled to it. Since fat and carbs are predominantly used for fuel, they are ideal candidates. So when dieting, maybe they should be calculated as a proportion of our energy intake rather per bodyweight, which is more appropriate for protein intake because it’s closely tied to body mass.
The important thing to remember is that there is always individual variability. That’s just something you have to acknowledge. Remember, in these articles I’m giving you practical application based on my interpretation of the research and my experiences. I’m not giving you the 10 Commandments of contest prep.
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