For gym-goers, sportspeople and anyone who is serious about their nutrition, today’s newspaper headlines are more than a little baffling, if not downright frustrating.

The “breaking news” and associated controversy centres around a publication by the National Obesity Forum in the UK, which states that fat won’t make you fat; carbohydrates and sugar will.

Apparently, this is news.

Yet, protein-sparing modified fasts have been the staple of bodybuilders for decades. Protein not only aids in the growth of lean muscle mass (given, of course, that one has stimulated the muscles and given them a reason to grow), but is known to have the highest satiety effects of any macronutrient. Fat is next on this ranking, whilst carbohydrates and sugar are pretty poor in terms of long-term satiety effects.

In other words, a carb-heavy diet is not as effective at promoting the growth of lean muscle mass, and gram for gram will not keep you as full, for as long, as a protein-rich meal.

Of course, the full story is a lot more complex. Fine tuning your diet and finding out what balance of macronutrients works for you is a process which can take years, and of course, it changes in response to the varying demands you put upon your body. There are also gender and hormonal differences, with women being far more tolerant of high-fat diets than men. Higher-fat diets can actually be very helpful to women in the promotion of lean muscle mass, given that fat consumption promotes oestrogen and testosterone production in women (Ingram et al., 1987), both of which are anabolic hormones (Henselmans, 2014). Fat has also been shown by some researchers to be more satiating for women than it is for men, although interestingly, this effect was nullified if the meal had a high salt content. In other words, both men and women ate more when their meals had a high salt content than low salt meals – it appears that high sodium content somewhat overrides our sensitivity to satiety (Bolhuis et al., 2016).

It is for this reason, for example, that high cocoa percentage dark chocolate is considered a very healthy alternative to milk chocolate. Although its fat percentage is considerably higher than high quality milk chocolates (though not, of course, than your standard ‘off the shelf’ mainstream bars), it is very low carbs and in sugar, and packed full of antioxidants and all of the other nutritional benefits found in chocolate. If you must consume chocolate, a bar high in natural, healthy plant fats is clearly preferable than one packed full of carbs and sugars. For women foods which are otherwise rich in fats (for example, salmon), high quality natural chocolate can be a very healthy addition to the diet. Menno Henselmans of Bayesian Bodybuilding, in his exceptional article ‘Why Women Should Not Train Like Men’ (packed full of research on diet and exercise for women – well worth reading in full) even points to research that shows that women with more fat in their diet actually burn more calories during exercise, have greater strength, and are leaner!

The only major flaw with the National Obesity Forum publication is that it claims calorie counting is a waste of time. To make this statement is to somewhat miss the punchline of their entire argument. Study after study has demonstrated that if you give people high carb meals, they will eat more before they feel full. In other words, they will consume more calories. Achieving weight loss is through the successful creation of a very simple inequality; energy in must be < energy out (energy in must be less than energy out). The best measure we have for this is the calorie.  

  

References:

Bolhuis, D., Costanzo, A., Newman, L., Keast, R. (2016). Salt Promotes Passive Overconsumption of Dietary Fat in Humans. The Journal of Nutrition 146(4).

Henselmans, M. (2015). Why women should not train like men. Available at:  http://bayesianbodybuilding.com/why-women-should-not-train-like-men/

Ingram, D., Bennett, F., Willcox, D., de Klerk, N. (1987). Effect of low-fat diet on female sex hormone levels. Journal of the Nartional Cancer Institute, 79(6).