Larger portions of food are being served. Larger portions have more calories. When combined with The Finish Your Plate Threat, large portions make you gain a lot of weight.

A 7-Eleven Double Gulp holds 64-ounces of soda and comes in at a whopping 800 calories. Most people are shocked when they hear that. Eight hundred calories is almost half the calories an average woman should eat in one day. That’s also 10 times the number of calories in the original Coca-Cola when it was introduced.

For some reason, people don’t think about larger portion sizes as having more calories. A drink is just a drink and a burger is just a burger. How big a food item is and its calorie count doesn’t spring to mind. It’s as if food performs a certain role in our mind and as long as it satisfies that role we are satisfied.

When thirsty we get a drink without consciously thinking about portions or calories, we just want a drink. Then we evaluate the drink based on value, convenience and taste, not nutrition, or calories, or portion size. We want the most for the money so we get the biggest item we can afford.

We are attracted to good deals offering the best value. That’s why value meals from fast food restaurants have been so stunningly successful. And that makes perfect sense. Who doesn’t want more for their money, especially on a good tasting food that’s immediately available?

But combine large portions with The Finish Your Plate Threat, which shows how people eat more from larger servings, and you have a recipe for obesity.

Americans are eating at least 200 more calories a day than we were in the 1970s. Some studies show we are eating up to 500 calories more a day. Over the same period, obesity has increased in adults and children, while portion sizes have jumped. Many people think larger portion sizes and increases in obesity are strongly linked.

Portion control has been shown by research to be the number one strategy needed to lose and maintain weight. If your portions are correctly sized, it’s almost impossible to gain weight. Yet over the years, portions sizes have gone up as cost has decreased, so finding proper portions has become difficult.

The very idea of a proper portion size has changed over time as we have come to expect big portions as the norm. Who wants a tiny 8-ounce cup of soda when we can get a 48-ounce cup of soda for the same price? The 48-ounce cup as become normal now.

The original McDonald’s meal had 590 calories. Now it has 1550 calories. A serving of McDonald’s french fries had 200 calories in 1960, 320 calories in the late 1970s, 450 calories in the mid-1990s, and 610 calories in the present.

A typical hamburger in 1957 contained a little more than one ounce of cooked meat. Today a typical hamburger has six ounces of cooked meat.

Bagels and muffins that used to be 2 to 3 oz are now typically 4 to 7 oz. A jumbo muffin has between 400 and 700 calories. Bagels have doubled in size and have the equivalent of six slices of bread, or over 400 calories.

Candy bars and potato chips used to be packaged in 1-oz servings are now marketed in 2- to 3-oz single-serving packages. A 2.1-oz Butterfinger has 270 calories and the 5.0-oz version has 680 calories. At one time I would automatically buy the bigger one without thinking about calories, because it seemed like a better deal. And so do most people.

Restaurant meals are growing too. Many meals now contain enough food for two people.

Are increases in portion sizes wrong or bad? Not once you realize what’s happening and adjust. But if you are like the 25 percent of people who clean their plates no matter how much food is on it, then it’s disaster. As food portions increase, so will your weight.

If you can learn correct portion sizes, as you will in the Perfect Portions Strategy, then increased portion sizes are a great value. You get more food for less money. The only problem is when you eat more food than you should.