Bulking and cutting: is it safe for your metabolism?

If you’ve ever spent time online trying to figure out the best way to build muscle or get in shape, you’ve probably come across a celebrity, athlete, or fitness influencer somewhere who advocates the “bulk up and down” method. to cut “.

Although this method is certainly not new – indeed, it became a phenomenon in the 1960s thanks to bodybuilders – it continues to be popular, even among amateurs, as many claim it is the best dietary method to effectively build muscle while losing fat. But it could actually be harmful, especially if tracked for a long time.

Bulking and cutting involve two distinct phases, which can lead to significant weight swings – at least for bodybuilders.

During the bulking phase, you consume a surplus of calories, usually from a diet high in protein and carbohydrates. This is believed to promote an “anabolic” (building) state, where you can build new muscle tissue and get bigger. For bodybuilders, this phase normally takes place during the off-season, when they are not competing. But many people who aren’t bodybuilders may choose to bulk up during the colder months.

Bulking also tends to lead to increased fat, which is why the cutting phase is necessary afterwards. This phase consists of eating in a caloric deficit in order to promote a “catabolic” state (degradation) which will lead to fat loss and better muscle definition.

On average, a volume is usually 4-6 weeks and a cut is usually longer, around 6-8 weeks.

Your metabolism

There is growing concern online that bulking and cutting cycles can “break” your metabolism. Indeed, this concern has an element of truth – even if it is not so simple.

Research shows that extreme weight loss – losing more than 60 pounds over 10-23 weeks – can lower your resting metabolic rate (the number of calories your body burns before you do any kind of physical activity), less in obese study participants. However, it is currently unclear whether this change remains permanent or not. This is why gradual weight loss is preferable, as research shows that it better preserves your resting metabolic rate.

Additionally, the more weight you gain during bulking, the more likely there is to be an increase in fat as well. More body fat means less insulin sensitivity. Over time, this could lead to type 2 diabetes. And, ironically, it can make it harder to build muscle because insulin needs to work properly to do so. But, at least in the short term, research shows that two weeks of overeating doesn’t seem to dull your ability to build muscle, even in overweight people.

Bulking phases can also lead to an increase in the number of fat cells, more so on severe swelling. Although dieting can reduce the fat actually stored in these cells, it does not reduce the number of fat cells we have. This can make it easier to gain weight in the future.

The relentless focus on nutrition with bulking and cutting could also lead to eating disorders. In fact, in a 2019 study of 348 female bodybuilders, 47% were identified as having an eating disorder, while almost half had used methods such as purging to control their weight. Whether a similar relationship exists in men has not been established.

How to do it safely

Ultimately, large weight fluctuations are associated with an increased risk of poor health and metabolic syndrome (the combination of diabetes, obesity, and high blood pressure). So if you’re considering trying bulking and cutting for any reason, it’s important to do so safely and without extremes to avoid the risk of injury.

Some people online advocate the “dirty bulking” method for gaining weight (and muscle) fast. This is done by consuming large amounts of calories, without forbidden foods. Some people may also use high calorie shakes and “mass gainers” (high calorie protein shakes) during this time.

But eating too many processed foods can cause cholesterol and blood sugar levels to rise, which can lead to heart disease and diabetes over time. Even in as little as four weeks, an unhealthy, high-calorie diet can see healthy young adults begin to show changes in their bodies that are associated with type 2 diabetes. Dirty swelling can also lead to a potential increase in liver fat, which can ultimately lead to liver damage in the form of non-alcoholic fatty liver disease.

There is no evidence that a dirty volume is better than a clean volume for building muscle. But given the potential harm that can come from an unhealthy, high-calorie diet — even just for a few muscles — it’s probably best avoided.

During the cutting phase, it is important to avoid using extreme methods such as supplements that promise to help you lose weight. Not only is there no evidence that these work, but some have even been linked to liver toxicity.

Although bulking and cutting may be a popular method, there is little evidence to suggest it is superior for muscle building or fat loss compared to other methods. But if you really want to try it, it’s better to do it in a “clean” way. During the bulking phase, avoid processed foods that are high in fat and sugar. Focus on eating nutrient-dense foods and only increase calories moderately (by about 500 calories per day) to avoid excessive weight gain.

When cutting, reduce calories moderately with the aim of losing only 0.5% to 1% of your body weight per week – or 0.4kg to 0.8kg per week for a person who weighs 80kg. Not only is it safer, but it will still help you achieve your desired fat loss without losing muscle.

Of course, you may be able to gain muscle without gaining fat, by only moderately increasing the amount of calories you consume daily. This will allow you to gain muscle slowly over time, while minimizing fat gain.