8 Surprising Causes of Weight Gain
With summer quickly approaching, now is the last time anyone wants to be worrying about weight gain. While any weight gain can be frustrating, it is especially tough when you aren’t sure why you are gaining weight.
Here we will explain 8 causes of unintentional weight gain so you can make sure none of these factors are hindering your wellness goals.
1. You’re Too Stressed
Some degree of stress is normal, but ongoing stress can lead to negative consequences for your body, including weight gain.
High levels of cortisol — a hormone that gets released in response to stress — has been shown to increase hunger levels. Not only that, but high cortisol levels increase your desire for calorie-dense, highly palatable foods (a.k.a. junk food).
It’s also been found that obese individuals tend to have higher cortisol levels.
This suggests that stress management may have a positive impact on weight maintenance.
In an 8-week study looking at 45 obese adults, participants who performed relaxation techniques such as deep breathing lost more weight than individuals who did not.
To reduce your stress levels, consider incorporating proven stress-busters into your routine. Some great options for fighting stress include:
- Meditation
- Deep breathing techniques
- Time spent in nature (walking, reading outside, lying in a hammock, relaxing on the beach)
- Yoga
It’s important to identify early when you’re stressed and burnt out. Here’s a complete guide to identifying and preventing burnout.
2. Your Diet Includes Too Many Highly Processed Foods
Ideally, a healthy diet would be made up of minimally processed whole foods such as yogurt (sugar and flavor-free), steel cut oats, fruits, and vegetables.
However, many individuals do not realise how many heavily processed foods they eat in a day. The processing these foods undergo causes them to be filled with harmful ingredients, excessive salt, added sugars, unhealthy fats, and preservatives.
Numerous studies have found a correlation between highly processed foods and weight gain.
For instance, a Canadian study completed in 2019 looked at over 19,000 adults and determined that individuals who consumed the most processed foods were over 30% more likely to be obese than individuals who ate the least amount of processed foods.
Along with less-than-ideal ingredients, processed foods are typically loaded with calories and lacking in nutrients.
A 2-week study following 20 people found that participants ended up eating around 500 additional calories a day on a highly-processed diet verses an unprocessed one.
Simply by avoiding processed foods as much as possible and focusing on whole foods instead can help slash calories from your diet with minimal effort. Try slowly incorporating more whole foods into your diet such as:
- Eggs (with the yolks!)
- Fresh or frozen vegetables and fruits
- Nuts and seeds
- Beans
- Oatmeal
- Unsweetened yogurt
- Homemade smoothies

Healthy, unprocessed food
3. You Consume Too Much Sugar
Excess sugar can have a negative impact on your waistline, and you may be consuming more than you realise.
Sugar is hidden in an alarming number of foods. There are the obvious offenders such as ice cream, candy bars, cookies, sports drinks, but sugar can also be found hiding in items such as bread, ketchup, soups, dressings, and more. Sugary drinks, in particular, are an especially damaging offender.
Many studies have shown a link between sugar intake and weight gain along with chronic health conditions such as heart disease and type 2 diabetes.
For example, a review of 30 different studies in almost 250,000 adults and children tied sugary beverages with weight gain.
One study in 11,218 women found that drinking just 1 soda a day resulted in a 2.2 pound weight gain over 2 years.
Try reading the ingredient labels on anything you buy to be aware of any added sugar. If you consume sugary drinks, try slowly switching to a healthier option such as water with fresh squeezed lemon.
4. You Lead a Sedentary Lifestyle
Inactivity is linked to chronic disease and weight gain. While you think you may not lead a sedentary lifestyle, you might be sitting more than you realise.
Think of how much time you spend a day sitting at a desk, using a computer, sitting in your car, watching TV. All these sedentary activities add up.
A study in 464 obese and overweight individuals discovered that they sat for an average of 6.2 hours on working days. Work-related duties were the largest offender, followed by TV watching.
The good news is that small changes can produce big results.
A 3-month study in 317 workers discovered that replacing 1 hour a day of sitting with standing reduced waist circumference and increased lean muscle mass.
Try adding small increments of activity throughout your day to help decrease the amount of time you spend sitting. Some great ideas include:
- Taking a walk during your lunch break
- Investing in a standing desk
- Riding your bike or walking to work
- Taking a walk before sitting down to watch TV
- Marching in place or doing jumping jacks or other exercises during television ads

Using a stand up desk can help you burn calories
5. You Yo-Yo Diet
Have you ever lost 5 pounds only to gain it all back (or maybe even more)? Welcome to yo-yo dieting. It’s a cycle that so many people fall into.
This common practice can lead to an increased risk of weight gain.
In a study following 2,785 individuals, those who were on a diet in the previous year weighed more and had higher waist circumferences than non-dieters.
Other studies found that restricted eating may cause negative changes to your body’s hunger hormones that can affect weight gain in the future.
To maintain weight loss for the long run, it is important to skip dieting and make healthy lifestyle changes instead.
6. You Don’t Sleep Enough
Can sleeping more help you lose weight? Yes! Healthy sleep is crucial for a variety of reasons, one of which is maintaining a healthy weight.
A study in 92 women found that those who got less than 6 hours of sleep each night had higher BMI’s (body mass index) and higher levels of a protein released by fat cells.
A 2-week study following 10 overweight adults on a low-calorie diet found that individuals who slept 5.5 hours at night lost 55% less fat than individuals who slept 8.5 hours each night.
If you struggle to get a healthy night of deep, restful sleep, consider trying some of these tips for better sleep:
- Diffusing calming essential oils such as lavendar
- Cutting off caffeine intake long before bedtime
- Going to sleep at the same time every night and waking up at the same time
- Limiting screen time at bedtime
- Getting a dose of physical activity every day
7. Mindless Eating
Do you eat while watching TV? Do you eat at your work desk? Mindless eating — eating without actually focusing on your food — can lead to excessive calorie intake and therefore lead to weight gain.
Wondering how to eliminate mindless eating? Try these tips:
- Stay occupied
- Get some form of physical activity daily
- Avoid eating while doing other activities such as watching TV, reading the newspaper, talking on the phone, or working
- Pay attention to your body and stop eating when you are full
- Include healthy fats, high-quality protein, and healthy carbohydrates in meals and snacks to keep you nourished and energised
- Take a short walk (even just 5 minutes) if you are feeling the urge to snack even if you aren’t actually hungry
- Take your time eating and focus on enjoying your food and listening to your body’s cues
8. You Don’t Drink Enough Water
Drinking water is important for overall health and can also be a helpful tool for weight loss.
Adequate hydration helps:
- Flush wastes from the body
- Keep you energised
- Help you feel fuller sooner
- Prevent you from confusing thirst with hunger
Here are some easy tricks for getting enough water:
- Use a water tracker – These handy devices keep a record of how much you drink each day and can help keep you on track to getting enough water.
- Stay Prepared – Carry a reusable water bottle so you always have hydration on hand.
- Get water through food – Fruits (especially watermelon!), vegetables, and homemade, broth-based soups are all excellent sources of hydration.
- Spruce up your water – Try added a wedge of fresh fruit or frozen berries to your water to add a bit of healthy flavour.
Are You on Track?
Knowing which factors can lead to unintentional weight gain can help you stay on track to your health and fitness goals.
Try working on one or two of the areas mentioned above and might be enough to see serious results — just in time for summer!
What are some of your favorite tips for losing weight for summer? Be sure to let us know in the comments!