A client recently asked me, “How often can I get away with eating junk food?” She knows that my nutrition philosophy is the “80:20 rule”: Eat healthy foods as often as possible (at least 80 percent of the time), but also enjoy the occasional less healthy food (less than 20 percent of the time), if that’s what you really want.
I’ve seen this approach work well with my clients who were previously chronic dieters yet hadn’t been able to lose weight. Once I give them permission to have “forbidden foods,” those foods lose their power and they’re able to make healthier choices the bulk of the time.
There is some evidence that “cheat meals” (although I hate that term) can help boost fat loss and mental health among dieters. Yet I wanted to give my client a more quantifiable answer. Could a few days of junk food or even a single fast food meal make a difference in your overall health?
Junk food and fast food defined
What is “junk food”? Essentially any food that is highly processed, high in calories and low in nutrients. Junk food is also usually high in added sugars, salt and saturated or trans fats. Some evidence points to junk foods as being as addictive as alcohol and drugs.
“Fast food” is food that is prepared quickly and is eaten quickly or taken out. Although there are a growing number of healthier fast food options, most fast food can still be classified as junk food.
Long-term effects of eating junk food
Eating a poor quality diet high in junk food is linked to a higher risk of obesity, depression, digestive issues, heart disease and stroke, type 2 diabetes, cancer, and early death. And as you might expect, frequency matters when it comes to the impact of junk food on your health.
A review of studies on fast food and heart health found having fast food more than once a week was linked to a higher risk of obesity, while eating fast food more than twice a week was associated with a higher risk of metabolic syndrome, type 2 diabetes and death from coronary heart disease.
This is disturbing considering nearly half of American adults eat fast food at least once a week.
Short-term effects of junk food
It’s human nature to think about benefits and risks over the short term rather than considering the impact our choices have over the long term. So how does consumption of junk food affect your body over the short term?
Just a few days of junk food could change your metabolism. A small study of 12 healthy young men found eating junk food for just five days led to a reduced ability of their muscles to turn glucose into energy, even though they didn’t eat more calories as part of the study. Over the long term, this change could lead to insulin resistance and eventually type 2 diabetes.
Another effect of just a couple of days of junk food is poor digestion. Because junk food lacks fiber, eating too much of it could lead to constipation.
That single fast food meal can narrow your arteries, leading to an increase in blood pressure.
And the quick spike in your blood sugar from eating junk foods high in refined carbohydrates and added sugars can cause a surge in insulin, leading to a quick drop in blood sugar. That leaves you feeling tired, cranky and hungry for more.
Just one serving of junk food can increase inflammation throughout your body. Further, an Australian study suggests that in people with asthma, a fast food meal high in saturated fat can increase inflammation in the airway, potentially making an asthma attack more likely. . So it seems the quick hit of junk food, while fleetingly rewarding, does carry short-term risks.
The good news: Every healthy meal helps
The amount of inflammation and oxidative stress your body will experience after eating occasional junk food seems to be a function of the “big picture” of your choices over time.
If you want to enjoy junk food once in a while but are concerned about the impact on your health, take a look at your overall health habits. Do you smoke or overdo it on alcohol? Are you exercising regularly and eating plenty of nutritious foods such as vegetables, fruit, legumes, fish, nuts and seeds, and whole grains? When it comes to your health, it seems you can “get away with” the occasional junk food more easily when you follow a healthy lifestyle most of the time. So think about your ratio of healthy to less healthy foods. Are you achieving 80:20 or is there room for some improvement?
When you’re making the choice between a healthier option and junk food, consider that just one healthy meal a day worked into the typical American diet could reduce overall stress and inflammation in your body. Every meal is an opportunity to positively impact your health.
Based on the current research, my advice to my client essentially remains the same: Once you’re aware of all of the short-term and long-term impacts of junk food and you still really want some, have it less than once a week and really savor it. Then get right back to enjoying nourishing, nutritious foods.
FAQs
In the short term, fast food impacts blood sugar and blood pressure, increases inflammation, and may mean an individual does not eat enough necessary nutrients. In the long term, a diet rich in fast food could lead to issues with digestion, immunity, inflammation, heart health, obesity, and more.
What does fast food do to your body? ›
In the short term, fast food impacts blood sugar and blood pressure, increases inflammation, and may mean an individual does not eat enough necessary nutrients. In the long term, a diet rich in fast food could lead to issues with digestion, immunity, inflammation, heart health, obesity, and more.
What are 5 symptoms from a health perspective of eating fast food? ›
Eating a poor quality diet high in junk food is linked to a higher risk of obesity, depression, digestive issues, heart disease and stroke, type 2 diabetes, cancer, and early death.
How fast food affects your health essay? ›
Junk food has high cholesterol and poor concentration. They are less nutritious and provide us with less energy. By eating junk food, fat accumulates in the body, and we become lazy. It gives rise to various health problems like obesity, diabetes, heart disease, blood pressure, etc.
Do you think fast food is healthy or unhealthy? ›
Fast food is typically loaded with calories, sodium, and unhealthy fat—often enough in one meal for an entire day. It also tends to be low in nutrients and almost totally lacking in fruit, vegetables, and fiber.
Can people have perfect bodies and eat fast food? ›
You can eat junk food and get in shape provided you monitor your calorie intake and meet your essential protein and fatty acids needs. Junk food should never make up the bulk of your diet, even if the food choices fit your calorie needs. Junk food isn't filling and may leave you feeling hungry.
What food does to your body? ›
A food is something that provides nutrients. Nutrients are substances that provide: energy for activity, growth, and all functions of the body such as breathing, digesting food, and keeping warm; materials for the growth and repair of the body, and for keeping the immune system healthy.
What happens when you stop eating fast food? ›
Cutting back on junk food means you'll be receiving less amounts of fat, sugar and calories, which will naturally lead to weight loss. You'll feel more energetic. Receiving more calories from junk food doesn't mean you're obtaining enough nutritional substance.
What are 5 negative effects of eating fast food or junk food? ›
Let us look at a few harmful effects of junk food that take a toll on your body as well as brain:
- Obesity. ...
- Learning and memory problems. ...
- Loss of appetite and digestion. ...
- Mental impact leading to depression. ...
- Inadequate growth and development.
Fast food is a popular choice for its taste and convenience, but it tends to be high in calories, sugar, and fat and low in nutrients. Eating fast food frequently may negatively affect multiple areas of your body, possibly increasing your risk of conditions including type 2 diabetes, obesity, and high blood pressure.
The better thing to do is eat something than to fast for a little while. Even if that something isn't the healthiest option.” On the other hand, eating poorly often results in health damage. “Long term, for repeatedly eating stupidly over months and years, is decreased health,” Brown said.
How often is fast food okay? ›
While eating fast food once a week will not pose any harm in the short run, once you start regularly indulging in cheat meals, all these ingredients can come back to haunt your body. Therefore eat smaller portions to reduce the intake of these hazardous ingredients and to keep your body safe and healthy.
Is eating fast food bad for you essay? ›
You become prone to cardiovascular diseases due to the consumption of bad cholesterol and fat plus sodium. In other words, all this interferes with the functioning of your heart. Furthermore, junk food contains a higher level of carbohydrates. It will instantly spike your blood sugar levels.
Are people who fast healthier? ›
Early results have found that some types of fasting may have positive effects on aspects of health like blood sugar control, blood pressure, and inflammation . But fasting can also cause weight loss.
What food does your body need the most? ›
Water is probably the most important essential nutrient that a person needs. A person can only survive a few days without consuming water. Even slight dehydration can cause headaches and impaired physical and mental functioning. The human body is made up of mostly water, and every cell requires water to function.
What is the most important meal in the body? ›
Breakfast is often called 'the most important meal of the day', and for good reason. As the name suggests, breakfast breaks the overnight fasting period. It replenishes your supply of glucose to boost your energy levels and alertness, while also providing other essential nutrients required for good health.
How much fast food is too much? ›
Remember that junk foods are okay to eat occasionally, but they should not make up more than 10% of your daily energy intake. In a day, this may be a simple treat such as a small muffin or a few squares of chocolate. On a weekly basis, this might mean no more than two fast-food meals per week.
What does fast food do to your brain? ›
Junk foods can hamper the signalling of neurotransmitters such as dopamine and serotonin (the happy hormones). This can lead to depression and other mental health disorders. Canadian researchers have found that fast food can often result in people feeling more hurried or impatient.
Does fast food affect mental health? ›
In addition to depression, eating too much junk food can worsen symptoms of anxiety. The refined carbohydrates found in a lot of fast food can cause your blood sugar to fluctuate, in some cases triggering panic attacks, insomnia, and symptoms linked to anxiety.
How long can the body fast from food? ›
Information about life expectancy is based on real world contexts, such as hunger strikes and serious medical conditions. With no food and no water, the maximum time the body can survive is thought to be about one week . With water only, but no food, survival time may extend up to 2 to 3 months.
The unhealthy fat which we eat followed by no physical activity gets stored in our body leading to weight gain which results in obesity. Junk food can adversely affect your metabolism: Our metabolism becomes so weak that after 5 days it takes time of 2-3 days for our body to function normally as before.
How long can the body fast without food? ›
In general, it is likely that a person could survive between 1 and 2 months without food. As many different factors influence the length of time that the body can last without food, this period will vary among individuals.
Why is junk food so addictive? ›
Eating junk food causes a release of dopamine in the brain. This reward encourages susceptible individuals to eat more unhealthy foods.
Does fast food cause depression? ›
People who eat a lot of fast food are 51 percent more likely to be depressed than those who steer clear of it, according to a Spanish study. The more burgers, pizza, and fries people ate, the greater their risk.
Is fast food once a week ok? ›
Fast food contains a lot of unhealthy ingredients like sugar, saturated fats, trans fats, and a lot of calories. While eating fast food once a week will not pose any harm in the short run, once you start regularly indulging in cheat meals, all these ingredients can come back to haunt your body.
What are the 10 harmful effects of junk food? ›
One of the most common side effects of junk food is this. Junk foods are high in calories, sugars, and fats, which are the major causes of weight gain. Obesity also induces joint pain, diabetes, and a variety of heart issues. As a result, it is crucial to restrict your intake of fast foods.
Why is fast food so unhealthy? ›
These fast foods typically contain multiple chemicals and synthetic ingredients. They are calorically dense, highly flavored, and nutritionally barren. Fast foods typically contain extra corn syrup, sugar, artificial sweeteners, salt, coloring agents, and other potentially disease promoting chemicals.
How often is too much fast food? ›
A review of studies on fast food and heart health found having fast food more than once a week was linked to a higher risk of obesity, while eating fast food more than twice a week was associated with a higher risk of metabolic syndrome, type 2 diabetes and death from coronary heart disease.
How much fast food should you eat? ›
According to a recent US study, you should eat fast food no more twice per week. The report of the link between fast food consumption and ill healthy shows that the more fast food consumed the greater a person's health risk.
How fast food affects your brain? ›
Junk foods can hamper the signalling of neurotransmitters such as dopamine and serotonin (the happy hormones). This can lead to depression and other mental health disorders. Canadian researchers have found that fast food can often result in people feeling more hurried or impatient.
Chick-fil-A focuses on quality food with simple ingredients, and it's one of the best choices for healthy eating on the go for fast food. As the name implies, the entire Chick fil a menu is based around chicken, which is generally a low-calorie and high-protein food.
What can I eat instead of fast food? ›
Consider stocking:
- Whole-grain breads and cereals, pasta, and prepared pizza crust.
- Milk, reduced-fat shredded cheese, eggs, canned tuna, canned beans, peanut butter, lean ground beef patties, chicken, and meatballs.
- Fresh, frozen, or no-added-salt canned vegetables; fresh and dried fruit; and fruit canned in juice.
10 Fast-Food Restaurants That Serve Healthy Foods
- Chipotle. Chipotle Mexican Grill is a restaurant chain that specializes in foods like tacos and burritos. ...
- Chick-fil-A. Chick-fil-A is a fast-food restaurant that specializes in chicken sandwiches. ...
- Wendy's. ...
- McDonald's. ...
- Ruby Tuesday. ...
- The Cheesecake Factory. ...
- KFC. ...
- Subway.
