October 7, 2021

Metabolism is the term used to describe the chemical reactions in the body’s cells that change food and drinks into energy, to be used or stored. Specific proteins in the body control the chemical reactions of metabolism. 

Thousands of metabolic reactions happen at the same time — all regulated by the body — to keep our cells healthy and working.

The problem is that, for many, metabolism slows as we age. We just can’t get away with eating and drinking like we used to. But why does metabolism slow and what can we do about it, better still, reverse it?

Although there may be many factors that influence our body’s metabolic rate, three common factors are:

  1. Years and decades of reduced physical activity. Your muscles work on a use-it-or-lose-it basis. Can you remember cars with stiff window winders? As muscle tissue is metabolically active, if we lose lean tissue our metabolism slows. 
  2. Dieting… specifically very low-calorie diets. These are often deficient in protein and cause loss of lean tissue, along with any fat loss. So, even if we have lost weight, after the diet our metabolism has slowed. Yo-yo dieting or severely reducing calories can play havoc with your metabolism.
  3. Protein deficient diet. We actually burn calories digesting food. It’s called the ‘thermic effect’ and it’s different for different macronutrients (proteins, carbs and fats). The thermic effect of protein is much higher than that of carbohydrate or fat. 

The mixed messages in the past that “If we eat fat, we get fat” OR “Reduce your calories and you’ll lose weight” have meant many people have actually upset their metabolism.

As your metabolism slows and your cells aren’t as active it can affect not just your weight but also your skin could become dry, your nails weak or flaky, and your hair more brittle.

An unpleasant side effect could be that when your body takes longer to break down and process your food choices, constipation could be an outcome.

Slow metabolism has been linked to insulin resistance so it’s good to reduce any foods or drinks that have a high carbohydrate (sugar) load.

Here’s something to think about. No doubt you’ve heard the terms “essential amino acids” (proteins) and “essential fatty acids” (omega 3 & 6 oils) but you haven’t heard a term “essential carbohydrates”. The lesson? Your body has no need for that bowl of rice when you eat an Asian meal. Rice delivers non-essential carbohydrates that your body has to metabolise and has a very low nutrient profile.

Here are some metabolism-boosting tips:

Eat optimal protein in all meals and snacks

Foods that are rich in protein use more energy to digest. Ensure that all meals and snacks have a protein serve in them. Keep your fridge stocked with meat, fish, cheeses, eggs, and full fat dairy (if you can tolerate). Keep whey protein powder in the pantry.

Flaxseeds are high in protein, fibre and omega-3 fatty acids and are an extra source of protein. Nuts and seeds do contain proteins but can be high in fat. Pulses contain protein but can be high in carbs.

Be aware of hard-to-digest foods

Some foods like wheat, soy, dairy and starchy vegetables affect some people’s digestion. This may not affect your metabolism but could make your stomach and bowels feel uncomfortable.

Eat more slowly

Take note of how you eat your meals. Do you sit at a table that is set for the meal with cutlery and napkins? Is the TV turned off? Do you eat with the family or housemates? Do you engage in conversation?

Be mindful of each mouthful, chew your food, and put down your knife and fork between each mouthful. If you eat too quickly you may overeat before your stomach realises that you are no longer hungry. 

To add fat or not

Essential fatty acids are a requirement for healthy bodily function. We have also learnt that fat is no longer the enemy when it comes to weight loss. Excess fat is the enemy. However, if your weight loss has plateaued or stalled then the overall calories from fat may need to be addressed. 

When eating higher fat proteins, it’s a good idea to avoid or reduce any extra added fat like olive oil, butter or a fatty sauce on the side.

Stay ahead of hydration

There is some evidence that when people eat less, their metabolism slows. But could this be because of a reduction in the water content of the food? If so, the slowdown in metabolism may not be just because of fewer calories but less water.

Plan to drink 8 glasses of water per day. Have a glass on waking, one with breakfast, lunch and dinner, and one before and after each snack morning and afternoon, that equals 8 glasses per day. 

There’s also a tiny argument for chilled water as your body will expend calories warming up the chilled water to normal body temperature. The effect is small though.

You may choose to use 2 x 1 litre water bottles, fill them at night, and work your way through them throughout the day. Don’t forget to count tea and coffee intake as well as any bone broth, soup, unflavoured mineral water, protein shakes or soda water in your hydration intake. It adds up quickly.

Reduced eating window from 12 hours to 10 hours

The longer you go without eating or drinking the lower your insulin levels drop. This utilises stored sugar in your fat cells as an energy source, and it may help break your plateau. 

How this looks is that you may have your first meal of the day at 9am instead of 7am and your last meal at 7pm instead of 8pm. This increases your overnight non-eating window from 12 to 14 hours. 

Good quality sleep

Getting a good night’s sleep is one of the best things you can do to reset your metabolism. It helps with maintaining your hormone levels.

Daily exercise or movement 

Mixing up your exercise routine may help. Ensure you have a mix of cardio and strength as well as some relaxation, stretching, yoga or breathe work.

Cardio is where you huff and puff. It could be walk/run, stairs, bike riding, Zumba, HIT training, swimming, gym classes. 

Strength or resistance work could be a simple as your gym circuit, push-ups, planks, and ball work, or walking up and down stairs with your groceries or some heavy bags.

Managing stress levels

Stress (particularly long-term chronic stress) can play a large role in what’s happening with your weight. Find one or more things that help you reduce stress and make it a daily priority to schedule 10-30 minutes to do these activities.

Eat spicy foods

Adding spices to your meals could have an effect on your metabolism. Adding ginger to hot or cold water is another option.


You may not like to hear this, but alcohol cannot be stored as it is preferentially burned for energy. This sounds good, except that during the time your body is burning your consumed alcohol it can’t burn stored fat. Consuming alcohol makes losing weight much harder.

The end goal – metabolic flexibility

People whose metabolism has slowed typically only have access to sugar from food and drinks and not the fat stored in their body’s fat cells.

By following the tips above, you can improve your body’s metabolic flexibility at any age. Need some help. Contact your nearest centre and ask about our program. We’ll help you get into the best shape of your life!