Buying shakes, counting points or stocking up on frozen meals – we have either all tried it or know someone who has.

Ways to count calories and fat come in many forms, and this diet has been around for years. Eating less fat and calories has been proven to cause weight loss, but there are some important things to know before restocking your pantry.

“In the late 1970s, science began to put together the facts that dietary cholesterol raised blood cholesterol and saturated fats from animal products were less healthy than other fats. Food processors began the trend of offering lower-fat and lower-calorie options in response to the public’s interest,” said Judy Trumpy, registered dietitian at Thielen Student Health Center.

Low-fat, low-calorie diets consist mainly of fruits, vegetables, whole grains, fish, lean meats and fat-free or low-fat dairy products. Extra fats are used sparingly. The diets generally follow the food pyramid plan, but cut out the “discretionary calories” that are normally allotted based on activity level.

Low-fat diets work for reducing calorie consumption because one fat gram contains nine calories. Both protein and fat contain 4 calories per gram.

In normal-weight individuals, fat should account for 25 to 30 percent of daily calories. Amounts lower than this may inhibit the body’s normal functions, said Terri Collins, senior in dietetics and student organizer for Iowa State’s National Nutrition Month activities.

“Fat makes up every cell in your body, provides energy when food is not available, regulates body temperature and is essential in numerous enzymatic and hormonal mechanisms. Fat also tastes good and gives food a certain mouth feel,” Collins said.

Low-fat, low-calorie diets were the main method for extremely obese people to lose large quantities of weight before surgeries came along, Trumpy said. Very low calorie diets, or VCLD, are implemented in hospitals occasionally for obese patients. This involves eating 600 to 800 calories each day.

Normal individuals who are slightly overweight and aiming to lose a small amount should aim for 1,200 to 1,600 calories every day. Using the suggestion of 25 to 30 percent of calories from fat, 300 to 480 calories should be from fat if you are eating within this range.

“If you eat fewer than 1,200 calories a day, you may not get enough nutrients,” Trumpy said. “It takes 3,500 calories to make a pound, so don’t expect weight loss immediately.”

She added that a one-half pound loss each week is a good goal. Eating 250 calories less than normal each day should achieve this goal. To lose one pound each week, cut 500 calories. It is a good idea to make the calories in, or eaten, less than the calories out, or used during exercise, by combining good dietary choices with increased physical activity.

“Activity will keep the metabolism up and help you lose weight at a steady pace,” Trumpy said.

Alisha Barr, junior in political science, began a low-fat, low-calorie diet after Spring Break last year, and has since lost 57 pounds. She recorded her normal intake before dieting, and nearly cut it in half. Barr based her calorie levels on articles she had read in health magazines, and ate around 1,200 to 1,500 calories each day.

“I learned that what you put in, you have to work off if you expect to lose weight,” Barr said.

Barr lowered her caloric and fat intake, but also focused on eating nutritious foods and exercising. She switched from white to wheat bread, from regular to soy milk, and from processed to natural foods. Exercise also became a priority everyday.

Barr found that for herself, dieting was more about willpower and changing her lifestyle than about genetics. Not only did the weight loss achieved through dieting make her healthier physically, but also she felt better mentally.

“One of the reasons I wanted to lose weight was because I have a family history for heart disease and diabetes,” Barr said.

After losing some weight, she noted many other benefits besides disease prevention. “I feel better about myself and my attitude is much different. It is empowering to see the change that I accomplished on my own.”

The reason why Trumpy believes low-fat, low-calorie diets like Barr implemented are so popular is because they are generally accepted by science.

“To lose body fat, energy in needs to be less than energy out. There is no other way to lose weight,” Trumpy said.

Some individuals get stuck in a rut with low-fat diets, said Trumpy.

“If you are going to try one of these diets, give yourself variety and include foods from all food groups so that you don’t get bored,” Trumpy said.

She recommends eating healthy 90 percent of the time, and giving yourself a break 10 percent of the time. This will allow you to splurge while keeping calories in check. Weighing weekly or every other week will allow for proper surveillance of weight loss without becoming too obsessive. When someone becomes overly concerned about weight, problems may ensue.

Restrictive dieting can morph into diseases such as anorexia if they are taken to the limit. Trumpy said these are often started when someone on a restrictive diet receives complements about their weight loss and enjoy the adulation.

“The person gets to a point where they are more focused on the number on the scale and eating as little as possible, that they lose all intuition about eating,” Trumpy said. “They become dissociated with their bodies, and at this point, should seek professional help.”

Collins agrees, adding that although more than half of Americans are overweight or obese, there are many people restricting calories and fat unnecessarily.

“When it comes to being healthy, it’s not the thinnest people or the heaviest people that live the longest,” Collins said. “It’s the people right in the middle. The eating of fats and monitoring of caloric intake is just like anything in life – moderation is key.”

Trumpy generally recommends low-fat, low-calorie diets to her clients, as long as they are done in moderation. Dieters need to be aware that lean muscle and bone may be lost before fat if decreased calorie intake is not combined with activity.

Beginning on a plan that offers healthy frozen meals may be helpful in teaching proper portion sizes, and eventually, the individual can serve themselves a correct amount of normal foods.

“The important thing is to learn to recognize hunger and fullness. It takes practice to know when to quit eating,” Trumpy said.