10 Foods To Avoid When Trying To Lose Weight

You probably think you know which foods to avoid when trying to lose weight, but it’s not always as obvious as it may seem. As a vast body of research continues to look deeper into our diets and weight loss, we are learning more about which foods are actually causing you to gain weight.

So what are the top ten culprits most likely to derail your weight loss attempts? Read on for the list of foods not to eat when you're trying to lose weight.

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1. Sugar-sweetened drinks

Although not strictly a food, this comes in at number one because sugary drinks cause significant weight gain. “Sugar-sweetened beverages” include any drink that has added sugar. Sodas make up a large proportion of sugar-sweetened beverages.

A large meta-analysis of studies looking at the relationship between sugar-sweetened drinks and obesity found that sugary drinks promote obesity in both children and adults¹.

As well as increasing your risk of becoming obese, sugar-sweetened beverages have been shown to increase the chance of developing metabolic syndrome and type 2 diabetes². Metabolic syndrome decreases your insulin sensitivity, leading to further weight gain.

Another problem with sugary drinks is that they aren’t actually food, and your body doesn’t register them as such. Therefore, sugary drinks don’t leave you feeling full, despite the high-calorie content³.

Our hunger is regulated by the nerve endings in the stomach and intestine, which detect food when it arrives. When that occurs, these nerve endings send a satiety signal to the brain. The gastrointestinal tract releases hunger-suppressing hormones when it comes in contact with food, and your stomach will secrete less Ghrelin hormone (hunger hormone) when it contains food.

This may be why fluids do not provide the same level of satiety as solid food. These fluids pass fast through the GI tract, changing the pace of nutrient absorption and the signaling process, resulting in less impact on the satiety hormones.

In turn, this can lead to you taking in calories from both a full meal and your drink...a surefire way to gain weight.

2. Candy bars

No surprises here. Candy bars are not only practically devoid of any nutritional value, but they wreak havoc with your blood sugar levels.

Candy bars are high in calories and low in nutritional value: the exact opposite of what you are looking for in foods to help you lose weight, i.e., low in calories and high in nutritional value.

Because candy bars raise your blood sugar levels quickly, they cause your pancreas to release a surge of insulin, which then leads to a crash in blood sugar levels. This, in the short term, will leave you craving more sugar…or another candy bar. In the long term, this is an increased risk for developing insulin resistance, obesity, and type 2 diabetes⁴.

3. French fries and potato chips

It’s not the potato in the chips that’s the problem. Boiled potatoes eaten in moderation can be healthy. The problem comes when the potatoes are processed, fried, and laden with salt. Studies have shown an association between potato chip/fry consumption and weight gain⁵ ⁶.

Fries are very high in calories. One medium serving of french fries has around 400 kcal⁷, which is almost double the calorie count of a medium-boiled potato⁸.

4. Foods high in added sugars

One of the major problems with added sugar is that lots of sugar-laden foods fall under the guise of being healthy. For example, low-fat and fat-free foods often have more sugar added to them than the full-fat versions to make them more palatable⁹.

Added sugar has been linked not only to obesity¹⁰ but also to increased incidence of diabetes¹¹ and cardiovascular disease¹².

5. Ice cream

Ice cream is high in calories and loaded with sugar; it’s both high in fat and sugar, a poor combination to consume when trying to lose weight.

One study showed that high-fat, high-sugar snacking changes serotonin metabolism in the brain, contributing to disturbed appetite control and risk of obesity. The same effect was not seen with high-sugar-only snacking¹³.

It appears that the worst combination for causing weight gain is this combination of high-sugar and high-fat, found in ice cream.

6. Cookies and cakes

Cookies and cakes are delicious, but they are high in sugar and fat, high in caloric value, and poor in nutritional value.

Commercial cookies and cakes often contain trans fats to help preserve them, but these fats have been linked to cardiovascular disease and some cancers, so it’s a good idea to avoid them¹⁴.

7. White bread

This is a common pantry staple, but it’s likely doing more harm to your waistline than you realize.

White bread is made from refined flour and has a high glycemic index, meaning that it causes a spike in blood sugar and subsequent insulin release when you eat it.

One large Spanish study showed that the consumption of more than two slices of white bread per day showed a significant, direct association with the risk of obesity¹⁵.

8. Fruit juices

Fruit juices are generally considered healthy. In fact, there are juice-only weight-loss diets. However, even without added sugar, the reality is that fruit juice is often very high in natural sugars, despite its pretense as a healthy beverage.

Although fresh fruit juice contains many of the vitamins, minerals, and phytonutrients that fruit contains, it lacks fiber. Fiber lowers the glycemic index of fruit so that it causes less of an impact on blood sugar levels. It also increases the satiety of fruit (leaves you feeling fuller) so that you eat less. Consuming fruit juice without the fruit fiber doesn’t have a satiating effect, and so you may end up drinking more juice and thus more sugar than you would if you ate the fruit whole¹⁶.

If you do want to drink fruit juice, consider blending it instead of juicing it, so that it retains some of the fiber. This way, you get similar health benefits to eating whole fruits. 

9. Pizza

This doesn’t apply to all pizzas. Commercial or take-away pizza is often loaded with cheese and other high-calorie toppings, and the base is regularly made of refined white flour (see #7, white bread). One thick crust, heavily topped slice of pizza can contain almost all of the calories for an average meal.

Pizza is almost always healthier when you make it yourself; opt for thin, whole wheat bases and healthy vegetable toppings with minimum cheese.

10. Ready-made meals

Regular consumption of ready-made meals has been shown to be linked to increased risk of central obesity and fat deposition¹⁷.

The major difference between homemade meals and ready-made meals is that with the latter you have no control over the quality of the basic ingredients or the amounts of added sugars, fats, or salt. Ready-made meals usually contain saturated fats, hydrogenated oils, food additives, and high salt and starch, which when consumed regularly can have a detrimental impact on your weight-loss journey and overall health.

The lowdown

There are some common guidelines that you can follow to ensure that you avoid foods or drinks that are likely to cause you to gain weight. Cut out any sugary drinks, and stay away from foods that are:

  • High-sugar

  • High-sugar and high-fat

  • Processed or ready-made

  • Refined carbs

  • Contain trans fats

A good rule of thumb is to stick to foods that are minimally processed and have as few ingredients on the ingredient list as possible.

  1. Sugar-sweetened beverages and weight gain in children and adults: a systematic review and meta-analysis (2013)

  2. Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis (2010)

  3. Effects of carbohydrates on satiety: differences between liquid and solid food (2011)

  4. A review of recent evidence relating to sugars, insulin resistance and diabetes (2016)

  5. Changes in diet and lifestyle and long-term weight gain in women and men (2011)

  6. Dietary patterns and changes in body weight in women (2006)

  7. Calories in french fries | Fatsecret

  8. Calories in boiled potato | Fatsecret

  9. A systematic comparison of sugar content in low-fat vs regular versions of food (2016)

  10. Sugar consumption and global prevalence of obesity and hypertension: an ecological analysis (2014)

  11. The relationship of sugar to population-level diabetes prevalence: an econometric analysis of repeated cross-sectional data (2013)

  12. Added sugar intake and cardiovascular diseases mortality among US adults (2014)

  13. Diet-induced changes in the Lean Brain: Hypercaloric high-fat-high-sugar snacking decreases serotonin transporters in the human hypothalamic region (2013)

  14. Trans fats | Science News

  15. Glycemic load, glycemic index, bread and incidence of overweight/obesity in a Mediterranean cohort: the SUN project (2014)

  16. Relationship between dietary fiber content and composition in foods and the glycemic index (1990)

  17. Consumption of ready-made meals and increased risk of obesity: findings from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) study (2015)

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