In HIIT & Fat Loss, Weight & Fat Loss, What to eat to lose fat

In this article, I outline how ineffective an increase in physical exercise can be on achieving a fat loss goal, unless your exercise regime is accompanied by a corresponding change in diet.

If you are confident that exercise alone will enable you to achieve your fat loss goals, then you can stop reading this article and head back to the gym; good luck! If on the other hand you want to better understand the most effective way to fuel and move your body in order to maximise the burning of excess body fat, then read on.

Firstly we need to understand the component parts of your body’s ‘Total Daily Energy Expenditure (TDEE)’. TDEE can be defined as ‘how many calories your body burns a day when exercise is taken into account’. Your TDEE is made up of:

  1. Basal Metabolic Rate (BMR) – BMR is the rate at which your body uses energy while at rest to maintain important functions such as breathing and keeping warm. BMR makes up the majority of your metabolism and accounts for around 60-70% of your TDEE.
  2. Non-Exercise Activity Thermogenesis (NEAT) – NEAT is the energy that we use for everything that we do that is not sleeping, eating or exercise. You will actually burn more calories from NEAT type activities in any 24 hour period, than you will from your daily exercise programme. Depending on the type of job that you do, NEAT can account for 25%-30% of your TDEE.
  3. Exercise Activity Thermogenesis (EAT) – EAT is the calories you burn from your exercise programme. There are a number of variables including the type and intensity of exercise, as well as your total body weight that will dictate how many calories you burn from exercise. EAT only burns between 10% & 15% of your TDEE.
  4. Thermic Effect of Food (TEF) – TEF is the amount of calories that your body burns to digest food and is between 5% & 10% of your TDEE.

You can now see that exercise only accounts for 10% – 15% of your Total Daily Energy Expenditure, which is not much. If you train for between 3 and 5 hours a week, then exercise only accounts for between 1%-3%  of your Total Weekly Energy Expenditure (TWEE).

The type of exercise you do, such as long steady state exercises (running, cycling etc) can stimulate hunger. Many exercisers reward themselves post workout with large portions of high calorie food and drinks which cancel out the fat loss gains from their training. On the other hand, exercises such as High Intensity Interval Training (HIIT) can suppress hunger.

If reading the above makes you feel like knocking your exercise regime on the head, then you need to play the long game and look at the wider benefits of exercise which includes (taken from the NHS website):

  • up to a 35% lower risk of coronary heart disease and stroke
  • up to a 50% lower risk of type 2 diabetes
  • up to a 50% lower risk of colon cancer
  • up to a 20% lower risk of breast cancer
  • a 30% lower risk of early death
  • up to an 83% lower risk of osteoarthritis
  • up to a 68% lower risk of hip fracture
  • a 30% lower risk of falls (among older adults)
  • up to a 30% lower risk of depression
  • up to a 30% lower risk of dementia

Exercising generally makes you feel good about yourself, especially as you start to notice your fitness gains, which can include improved cardio vascular fitness, muscular endurance, as well as loss of excess body fat. Exercise can improve your overall mood, your relationships with others, as well as your ability meet the physical and mental demands of everyday life.

So to enhance the positive effect of your exercise programme, especially if fat loss is a key goal, you need to do the following, in order of priority.

  1. Reduce your calorie intake by 500 calories a day. This would result in a fat loss of 1lb a week, which is realistic and sustainable fat loss goal. It is easier to cut out 500 calories from your diet, than it is to burn them off through exercise.  The easiest way to achieve the maximum daily calorie reduction is to cut out or significantly reduce your alcohol consumption. Alcohol makes you store calories as fat, as well as reduces your body’s ability to burn fat as fuel. When you drink alcohol you also tend to make poorer food choices, which add to your fat stores. You can also significantly reduce the amount of calories you consume by cutting out refined sugary foods, which cause an insulin spike and a corresponding increase in body fat storage.
  2. Increase the amount of calories burnt by NEAT. You simply need to move more as part of your everyday life, as everything counts here. Walk more, get off the bus one stop early, take the stairs a few flights at work, get a standing desk; I think you get the idea. This all helps to speed up your metabolism and burn more calories which contribute towards your fat loss goal. Increasing calories burnt by NEAT will have a far bigger impact on your fat loss goals than increasing your volume of exercise.
  3. Incorporate High Intensity Interval Training (HIIT) into your weekly training schedule. HIIT not only burns a lot of calories during the actual training session, but it also raises your BMR for up to 38 hours afterwards, which means that your body burns more calories at rest for long after you have completed your training session, so you will burn more calories even while you sleep!

In summary – Eat well, move more; in that order.