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Can eating too little make you fatter?

As a fitness expert who has coached hundreds of people over the years, one thing that can be difficult to achieve is to get clients to understand is the complex relationship between eating and fat loss. You’d be forgiven for thinking that cutting your calories from eating and drinking while increasing your exercise was all you needed for fat loss, but the reality is more complex as is explained by Dr. Layne Norton in this episode of ‘Mind Pump Podcast’.

In it Dr. Norton, makes the point that if you eat too little for too long a phenomenon can occur where you actually get fatter even though you’re losing weight. How can this be?

The first thing that we need to understand is that fatter doesn’t always mean weighing more. It is possible to lose weight and gain fat as a body weight percentage. I’m sure you’ve heard the term ‘skinny fat’, well this is a skinny person that may or may not have lost weight who has still got a lot of fat around the organs. So if you’re weighing less but not noticing fat loss then it’s more than likely that you’re actually losing muscle mass. For example, if you lose 10lbs of muscle and 5lbs of fat then your fat-muscle ratio actually increases.

This phenomenon isn’t just limited to normal people looking to lose fat. Sometimes athletes and professional bodybuilders don’t understand this fundamental issue and actually take backward steps when cutting weight for competition, losing muscle mass and decreasing performance.

Dr. Norton agrees that gaining lean muscle mass is the most effective way of cutting down on your overall body fat percentage. You might see your weight increase on the scale but if you put on 5lbs of muscle and your body fat stays the same, as a percentage your body fat is lower, and it will show in the mirror. I go into this a bit more in the blog Weight Loss vs Fat Loss.

In the podcast, Dr. Layne Norton, Ph.D. explains that the solution is to stop putting people on restrictive diets and actually increase the amount of nutritious food we eat.

Based on research he mentioned that resistance training plus calorie restriction seems to give the best results with muscle retention. Whereas calorie restriction on its own resulted in a loss of muscle mass. Also it is worth knowing that calorie restriction plus cardio actually results in more muscle loss than calorie restriction alone.

scales and measuring tape

People get very hung up on a number on a scale and worry less about what is going on internally. Human beings are highly subjective and if we see that a scale shows that we weigh less then we automatically believe that we have lost fat even if in actuality we’ve lost muscle too.

A big argument for adding additional nutritious food is that if your proteins and essential fats are too low then you will struggle to maintain and build muscle. If you lose muscle then you lose physical capacity to burn calories and lose fat. Your metabolism also slows as your body reacts to the nutrition deficit and becomes more efficient with how it expends energy.

Unless you’re living in the wilderness where food is scarce then you really don’t want a more efficient (slower) metabolism. In the modern world of convenience foods a slower metabolism no asset at all. It is a hindrance that makes it more difficult to burn fat.

Hadza tribe montage

Interestingly while studying the hunter-gatherer Hadza tribes of Tanzania, the analysis showed that they burned roughly the same amount of calories as the average Westerner despite being far more active throughout the day. This is because their body’s metabolism has adapted over time by slowing down and becoming more efficient.

The human body has the capability of being very thrifty with calories, for example, prisoners of war being forced to live on a few hundred calories a day. Or they can be extremely less efficient like a professional bodybuilder eating 3500 calories+ a day. Therefore, eating too little for too long can actually work against the objective of fat loss.

Bodybuilder posing

If you train to build muscle consistently your metabolism will become less efficient, burning more calories. This is a difficult concept for your average person to grasp, especially when in all other facets of life, more efficient equals “better” and less efficient equals “worse”. It’s a complete reversal. To go back to our favourite car comparison a less efficient metabolism would be driving in too low a gear all of the time, burning fuel (calories) quicker per mile, and a more efficient metabolism would be driving in the correct gear, getting better mileage.

Another effect of heavily reducing calories is that you might find that you’re less motivated to move and exercise, and generally feel more lethargic. Studies show that people will sit more and do less non-exercise activity (go for walks, do the housework, tend to the garden) while they are dieting. This kind of exercise usually makes up more of your daily calorie burn than planned exercise.

In fact, a person who trains 4-5 (1 hour at a time) days a week can still be considered sedentary if they are not moving nearly enough the rest of the day. This is one of the by-products of modern work environments where people tend to be sitting behind a desk for up to 8 hours a day.

Working at a desk

Severe calorie restriction can also affect your hormones because they start to shift to fat storage. The commonly used term for this is survival mode. This is because eating too little and not consuming enough nutrients is a stress on the body that triggers hormones to try and protect the body from death.

Also restricting calories for too long can result in binges. After restricting calories for too long, appetite increases and it’s all too easy to give in to temptation and go on an eating spree, especially when on a holiday. This compounds fat gain because the body has lowered its metabolism to burn calories more efficiently, then all of a sudden it gets an influx of calories that it can do nothing with except store as fat. So going too far in one direction (calorie restriction) can lead to an opposite reaction (sudden weight gain). This is why a lot of people revert back to their original weight fairly quickly when they finish dieting.

Calorie restriction can also lead to nutrition deficiencies. If you’ve been restricting your calories significantly then you’re going to end up with a nutrient deficiency. unless you’re taking vitamin supplementation and eating very nutritionally dense food.

So that is my summary of the podcast. If you’re looking to learn more then I hope you’ll give it a listen.

“Strength for Life”



Davie McConnachie

Davie McConnachie is Scotland’s leading health and wellness coach, multi-award-winning gym owner, motivational speaker and the founder of DMC Fitness, a fitness education facility known as the premier choice for 1-2-1 personal training. He has inspired thousands of people to fall in love with fitness – his true purpose and mission in life.

Diving into the world of fitness and wellness has helped Davie to deal with his own trauma and inner demons. He, overcame many dark times using his own unique methods to continue his cycle of healing.