Written by: Kevin Cann
Yesterday when I went into TPS I had a conversation with one of our members. She was telling the story of how she lost over 100lbs while being on a Paleo diet. She told me that she ate nothing but veggies and meat, avoiding added fats and even fruit. She also took up running, averaging roughly 25-30 miles per week. She lost weight, but lacked energy and in her own words, she had no muscle definition.
This member went from being 254lbs to a pretty jacked 140lbs by switching up her diet a bit and her training routine. This story is not dissimilar to many others out there attempting to lose weight. With so much information out there blaming both carbohydrates and fats for weight gain, along with articles touting that cardio is the best way to lose weight, it can be extremely difficult for someone to make the proper decisions to lose weight and be healthy throughout the course of a lifetime.
Both carbohydrates and fats, when eaten in excess, can most definitely lead to weight gain. The key is, when they are eaten to excess. When we decide to take part in a training program, our dietary needs change quite a bit. One major way in which our dietary needs change is our need for carbohydrates.
Carbohydrates breakdown into glucose. Glucose is a primary energy source for our muscles to fuel us through a tough training session. Glucose is taken up into muscle tissue through a transporter known as GLUT4. Exercise increases GLUT4 expression in skeletal muscle which can help regulate blood glucose levels and improve insulin action (1). This adaptation does not take months to happen. In fact, acute exercise can increase GLUT4 expression in patients with type 2 diabetes, who are believed to have a dysfunction in this transporter (2).
Most of these studies use some form of cardio performed for 45-60 minutes at a VO2max between 60% and 70%. Studies have shown that strength training can be an alternative to endurance training for type 2 diabetics. Strength training for 30 minutes 3 times per week led to an increase in GLUT4 expression (3).
Why would muscles increase their expression to the GLUT4 transporter in response to exercise? Because they require glucose to fuel the exercise and to replenish lost energy. What happens if we do not feed them the required energy they are craving?
We store roughly 1500-2000 calories of glycogen in our liver and skeletal muscle. A sedentary individual will burn roughly 600 calories of glucose per day. This number increases with exercise. If we cut out carbohydrates completely and take up exercise, we may be able to last roughly a week before we are out of energy. In this week we may have dropped 5lbs or more of weight, giving us a false sense that something great is happening. This tends to be water weight since carbohydrates hold on to water. This can be dangerous as it can increase our chances of becoming dehydrated.
This also means that your energy to workout at higher intensities has dwindled. You will begin utilizing fat as energy, which cannot support higher intensities due to the time it takes to oxidize the fat for useable energy. You might be thinking that this sounds great and you want to be burning fat.
However, when our muscle glycogen gets low our performance decreases, even in endurance sports where fat is the primary fuel. This is a defense mechanism instilled in us from times of food shortages. Our body will down regulate metabolic processes to conserve energy until our next meal comes along.
This will actually increase our hunger. As insulin drops due to not eating carbohydrates, so does leptin. Leptin is the hormone that causes us to be hungry when it is low and satiated when it is high. You may be able to say no to those food cravings in the beginning, but eventually you will cave. This also happens if we eat too few calories as well.
At the same time, if we eat too many carbohydrates we may gain weight. If our glycogen stores are full and we continue to pile on the carbohydrates, they need to get shoved into fat cells for storage as there is nowhere else to go.
This is why it is so confusing for people. On one hand if you eat too little you run into hunger cravings and if you eat too much you put on weight. How is someone supposed to know how many carbohydrates to eat in a day? The problem with this question is, it is different for everyone.
For someone that is taking part in exercise, I like to start everyone off with 150g-200g of carbs per day. This covers the 600cals of glucose required per day plus some extra for the training. Any extra glucose needed we can derive from the protein in our diet. I am a fan of taking in the majority of carbohydrates after the training session of the day, but sometimes this just does not fit into someone’s schedule. The reason for this is the acute increase in GLUT4 expression after exercise. More glucose is likely to be taken into the muscles at this time.
From here we pay attention to energy, sleep, hunger cravings, and performance in the gym. If performance is decreasing and energy feels low then we will make adjustments to the carb intake. If someone is constantly feeling hungry we will increase the serving size of protein with each meal. Protein starts at 4-6oz per meal for women and 6-8oz for men. I encourage people to eat 2-3 servings of vegetables per meal. Non-starchy veggies carry minimal calories and expand the stomach to help with hunger, not to mention they are rich in nutrients. The rest of the calories come from fat.
There is even constant tweaking that has to happen as we go along because things change. The first step in making dietary changes is just switching to eating a nutrient dense diet. Eat plenty of veggies, fruits, meat, fish, eggs, and healthy fats. If you do this and are not losing weight try the suggestions in this article and continue to tweak the macros until you find your sweet spot.