Researchers wanted to know if eating three servings of full-fat dairy products each day could help adults lose weight. They studied 74 adults who were overweight for 12 weeks. Some people ate dairy while cutting calories, some ate dairy without restricting calories, and others ate less dairy while cutting calories. The results showed that people who combined dairy with calorie restriction lost weight and improved their body composition. Interestingly, eating full-fat dairy didn’t prevent weight loss, and it helped people get more protein and calcium in their diets.

The Quick Take

  • What they studied: Whether eating three servings of full-fat dairy products daily affects weight loss, body shape, metabolism, blood cholesterol levels, and overall diet quality in adults who are overweight.
  • Who participated: 74 adults with an average age of 36 years who were overweight or obese. They were divided into three groups that followed different eating plans for 12 weeks.
  • Key finding: Adults who ate three servings of full-fat dairy while reducing their calories by 500 per day lost weight and improved their body composition. Eating full-fat dairy didn’t prevent weight loss, even when people weren’t restricting calories as much.
  • What it means for you: If you’re trying to lose weight, including full-fat dairy products like milk, yogurt, and cheese may be helpful and won’t sabotage your efforts. However, this is just one study with a small group of people, so talk to your doctor before making major diet changes.

The Research Details

This was a randomized controlled trial, which is one of the strongest types of research studies. Researchers randomly assigned 74 adults into three different groups. One group ate low-fat dairy and cut 500 calories from their diet. Another group ate three servings of full-fat dairy while also cutting 500 calories. The third group ate three servings of full-fat dairy without cutting calories. All groups were encouraged to follow Canada’s Food Guide, which is similar to nutrition guidelines in other countries. The study lasted 12 weeks, and researchers measured changes in weight, body shape, blood cholesterol, and what people were eating.

This research design is important because it allows researchers to compare what happens when people make different choices about dairy and calories. By randomly assigning people to groups, researchers can be more confident that differences in results are due to the diet changes, not other factors. The 12-week timeframe is long enough to see real changes in the body, but short enough that people can stick with the study.

This study was published in The Journal of Nutrition, a respected scientific journal. The researchers registered their study before it started, which is a good sign of transparency. However, the sample size of 74 people is relatively small, so results may not apply to everyone. The study was single-blinded, meaning participants knew what they were eating but researchers analyzing some data didn’t know which group people were in, which helps reduce bias.

What the Results Show

The most important finding was that people who ate three servings of full-fat dairy while cutting 500 calories per day lost weight and improved their body composition compared to those who ate low-fat dairy with the same calorie restriction. This suggests that the type of dairy matters less than overall calorie intake when trying to lose weight. Interestingly, people who ate three servings of full-fat dairy without cutting calories also saw some benefits, including a small decrease in hip circumference. This was surprising because eating more food without cutting calories usually doesn’t lead to weight loss. The researchers also found that people who ate the full-fat dairy consumed more protein and calcium, which are important nutrients for bone health and muscle maintenance.

People in all groups improved their compliance with Canada’s Food Guide over the 12 weeks, reaching 77% compliance by week 12. This shows that people can stick with healthier eating patterns when they’re motivated. The study didn’t find major differences in blood lipids (cholesterol and triglycerides) between groups, which is important because some people worry that full-fat dairy raises cholesterol. However, this doesn’t mean dairy has no effect on cholesterol—it just means the differences weren’t large enough to detect in this study.

Previous research has suggested that eating dairy products may help with weight management and reduce risk factors for metabolic syndrome (a group of conditions that increase disease risk). This study supports those findings by showing that full-fat dairy can be part of a healthy weight loss plan. The finding that full-fat dairy didn’t prevent weight loss contradicts some older beliefs that all fat in food is bad for weight management. This aligns with more recent research showing that the type of fat and overall diet quality matter more than just avoiding all fat.

The study only lasted 12 weeks, so we don’t know if these results would continue over months or years. The sample size of 74 people is relatively small, which means results might not apply to everyone, especially people of different ages, backgrounds, or health conditions. The study was conducted in Canada and followed Canada’s Food Guide, so results might be different in other countries with different dietary guidelines. The study didn’t track whether people maintained these eating habits after the 12 weeks ended. Additionally, the group that ate dairy without restricting calories was small, making it harder to draw firm conclusions about that approach.

The Bottom Line

If you’re trying to lose weight, including three servings of full-fat dairy products daily as part of a calorie-controlled diet appears to be safe and may be helpful. This could include milk, yogurt, and cheese. However, this is based on one 12-week study, so consider it as one piece of evidence rather than definitive proof. Talk to your doctor or a registered dietitian before making major diet changes, especially if you have health conditions or take medications that might interact with dietary changes.

This research is most relevant to adults who are overweight or obese and interested in losing weight. It may also interest people concerned about getting enough calcium and protein in their diet. People with dairy allergies or lactose intolerance should not follow this approach without finding suitable alternatives. If you have high cholesterol or heart disease, consult your doctor before increasing full-fat dairy intake, though this study suggests it may not be harmful.

In this study, people saw measurable changes in weight and body composition within 12 weeks. However, realistic expectations are that it takes 2-4 weeks to notice changes in how you feel and look, and 6-8 weeks to see significant differences in weight and measurements. Results depend on following the eating plan consistently and combining it with other healthy habits like physical activity.

Want to Apply This Research?

  • Track daily dairy servings (milk, yogurt, cheese) and note the type (full-fat vs. low-fat). Also track total calorie intake if weight loss is your goal. Measure weight weekly and hip/waist circumference monthly to monitor changes in body composition.
  • Set a daily reminder to include three servings of dairy in your meals. For example: milk in breakfast cereal, yogurt as a snack, and cheese with lunch. If you’re also cutting calories, use the app to log meals and stay within your calorie target while ensuring you hit your dairy goal.
  • Use the app to track dairy intake consistency over 4-week periods. Monitor weight trends rather than daily fluctuations. Take body measurements monthly. Note energy levels and how you feel, as improved nutrition often leads to feeling better before seeing major weight changes. Set a 12-week check-in to assess progress and decide whether to continue or adjust the approach.

This research summary is for educational purposes only and should not be considered medical advice. The study involved a specific group of adults over 12 weeks, and results may not apply to everyone. Before making significant dietary changes, especially if you have existing health conditions, take medications, or have food allergies or intolerances, consult with your healthcare provider or a registered dietitian. This single study, while well-designed, should be considered alongside other research and your individual health needs. Do not use this information to replace professional medical or nutritional guidance.