Weight Gain: 6 Factors That Predict It

by Troy Purdom and Len Kravitz, PhD on Jun 23, 2015

Fitness professionals expend a lot of energy helping people to lose weight, but there’s another way to view this challenge: What are the main factors that cause people to gain weight?

Understanding the specific behaviors that increase the risk of weight gain is essential to helping clients manage their weight. While most weight management articles focus on strategies and behaviors for losing weight, we will examine the other side of the coin: six factors that predict weight gain over the American lifespan.

1. Eating High-Calorie Foods

Mozaffarian et al. (2011) found that eating behaviors associated with progressive weight gain over multiple 4-year periods included regular consumption of

  • potato chips and potatoes (french fries; mashed, baked and boiled potatoes);
  • red meat, processed meats (bacon, salami, sausage and luncheon meats) and unprocessed red meats (beef, hamburger, pork, lamb or game);

  • butter, sweets and desserts; and

  • refined grains (foods like white flour and white rice).

Foods that help with weight management. Studies also found that eating foods such as nuts, whole grains, fruits, vegetables, yogurt, diet (zero-calorie) soda, cheese and milk (low-fat, skim and whole) appeared to curb weight gain. Mozaffarian et al. (2011) explain that these foods have slower digestion rates (some being high in fiber) and appear to enhance satiety—the feeling of being full after a meal.

These foods can replace other, more highly processed foods in the diet, creating a reasonable biological mechanism whereby people who eat more fruits, nuts, vegetables and whole grains may gain less weight over time (Mozaffarian et al. 2011).


2. Consuming Sugar-Sweetened Beverages

Sugar-sweetened beverages (SSBs) have little nutritional benefit and are reportedly the greatest provider of kilocalories in the American diet (Dennis, Flack & Davy 2009). In 2006, Malik, Schultz & Hu concluded that these drinks accounted for approximately 8%–9% of total energy intake in children and adults. SSBs contain carbohydrates of various forms, such as high-fructose corn syrup, sucrose and artificial sweeteners. Drinking SSBs has little impact on satisfying hunger (Malik, Schultz & Hu 2006), so people can consume large quantities without suppressing their appetite (Mattes 2006). 


The body’s response to carbohydrate (of equal caloric value) differs depending on whether it is liquid or solid. In a crossover study, DiMeglio & Mattes (2000) found that people who drank SSBs gained significantly more weight than they did when consuming a comparable amount of carbohydrate in solid form. Subjects participated in both treatments, following each for 4 weeks, and the SSB treatment produced double the fat mass compared with the solid-carbohydrate intervention. Both carbohydrate sources were the caloric equivalent to three 12-ounce sodas per day in both treatments (DiMeglio & Mattes 2000).

3. Sleeping Too Little (or Too Much)

Although more clinical trials are needed, several epidemiological studies suggest that weight gain is influenced by sleeping less than 7 hours or more than 8 hours per night (Marshall, Glozier & Grunstein 2008). According to Marshal and colleagues, people who sleep too little develop chronically impaired glucose metabolism, steadily contributing to obesity. In addition, sleep deprivation significantly lowers circulating levels of the hormone leptin and increases circulating levels of the hormone ghrelin—both effects that promote food intake (Van Cauter et al. 2008). 


Altering the regulation of these hormones contributes to increased hunger and appetite, especially for carbohydrate-rich foods linked to weight gain (Van Cauter et al. 2008). Ideally, sleeping 7–8 hours each night complements a successful weight management program.


4. Watching a Lot of TV

Length of time spent watching television is highly correlated with weight gain, especially in young people (Chapman et al. 2012). Chapman and associates tell us 58.9% of Americans watch television for more than 2 hours per day. According to these authors, epidemiologic studies reveal that those who regularly watch more daily television per day tend to

  • snack more while watching;

  • have higher overall caloric intake of foods; and
  • consume more energy-dense foods.

All these choices lead to weight gain.

Other evidence indicates that visual images of palatable food (as regularly seen in food commercials) evoke increases in plasma ghrelin concentrations, thus boosting the hunger/eating response (Chapman et al. 2012).

For the other two factors, as well as a full reference list, please see "6 Key Factors That Predict Weight Gain" in the online IDEA Library or in the May 2015 issue of IDEA Fitness Journal. If you cannot access the full article and would like to, please contact the IDEA Inspired Service Team at (800) 999-4332, ext. 7.

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About the Authors

Troy Purdom

Troy Purdom IDEA Author/Presenter

Len Kravitz, PhD

Len Kravitz, PhD IDEA Author/Presenter

Len Kravitz, PhD, is the program coordinator of exercise science and a researcher at the University of New Mexico in Albuquerque, where he recently won the Outstanding Teacher of the Year award. Len was also honored as the 2006 Fitness Educator of the Year by the American Council on Exercise.