Episode 80 – Nutrition For Fat Loss Part 2


In part 1, we discussed the concept of calories in versus calories out, how to figure out how many calories you need and some trouble shooting.  

Key Topics Covered

  • Why people may report that low calories is not working for them 
  • Protein intake and body composition outcomes 
  • Low carb VS low fat 
  • And how hormones play a role in fat loss 

Why Do People Report Low Calories Not Working? 

  • It never happens in research where all meals are provided. This topic has been studied a lot too. 
  • It only happens in the real world.  
  • I prefer not to speculate too much since the simple answer is that more calories are being consumed than reported. So it would mean we would have to be speculating about WHERE/HOW that is occurring. 
  • Often it is completely unintentional underreporting. 
  • One thing we can agree on with this model of thinking: If somebody ate 0 calories per day for weeks on end, there weight certainly could not increase, since the body is made up of calories. It would have to decrease. So then the next step is – surely there is somewhere between 0 and “low calories” where the same logic holds true.  
  • And then based on this logic, the only way “low calories” couldn’t work is if the body down-regulated energy expenditure to the point that it matches it. But the body is always burning calories for a purpose 


  • Since the goal is fat loss, not just weight loss, it makes sense to focus on retaining muscle in the process. 
  • Calories control what we weigh. As an oversimplification, if the calories dictated that we lost 8kg overall, but one version of you focused on muscle retention and the other didn’t, the outcome could be different.  
  • One version could lose 8kg of body fat and 0kg muscle. Other could lose 5kg of fat and 3kg of muscle. Even though they both had the same sized deficit, the one that focused on muscle retention lost more body fat. 
  • The reason that is oversimplified is because muscle and fat contain slightly different calorie amounts. So technically the same sized deficit would result in slightly different weight-loss. 
  • Either way, a good protein target to aim for is probably 1.6-2.2g/kg of total body weight per day. 
  • If you are super lean or in a large deficit, I would go a bit higher. If you are not very lean at all, I would drop it down to ~1.4g/kg/day, since our protein needs are more based on how much muscle we have.  
  • If these numbers are unrealistically high for you, just do what you can. Consistency matters most.  
Red Meat and Fish

Low Carb vs Low Fat 

  • While there has long been a debate over low carb vs low fat for fat loss, it does not matter much. 
  • Research has shown that both in controlled AND uncontrolled settings, aiming for either a low carb diet or a low fat diet with total calories and protein matched leads to similar outcomes on average. 
  • It is worth knowing theoretically that carbs have 4kcal/g and fat has 9kcal/g. But although fat has >2x the amount of calories per gram, it doesn’t matter much due to changes in satiety and desire to eat. 
  • I don’t encourage going super low fat, solely for hormonal reasons. But anything above say 0.4g/kg/day should be fine. And the rest is mostly personal preference. 
Train low high carb versus low carb

How do Hormones Fit in? 

  • We discussed this in episode 55 in more detail. It is a huge topic that absolutely deserves more time so I would encourage listening to that if you are interested.  
  • The short version is that hormones effect BOTH calories in and calories out. 
  • For example, decreased thyroid hormones and leptin can lead to a reduction in energy expenditure. 
  • Increased ghrelin could lead to an increased energy intake due to increased hunger. 
  • Hormones literally play a role in CICO. 
  • Beyond CICO they obviously play a role in body composition too. We can clearly see how hormones like testosterone effect body composition.  

Insulin plays a role. But evidence from low carb vs low fat studies showing the same fat loss when calories and protein are the same make it clear that it isn’t the driving force in all of this. 

Relevant Links/ Resources

Studies mentioned:

Underreporting study

Uncontrolled low carb vs low fat showing similar outcomes 

Controlled low carb vs low fat showing similar outcomes

Related Blog Posts:

hormones, low carb or fat, tracking

Common Criticisms of the Calories in vs Calories Out (CICO) Model

On Low Calories and Not Losing Weight

Low-Fat vs Low-Carb: What is Best for Weight-Loss?