Scientists studied whether eating more protein and fewer calories could help people lose weight, especially those who carry a specific obesity gene. Sixty people with extra weight followed a strict diet for 4 weeks, eating about 800 calories and 100 grams of protein daily. The results showed that people lost weight and reduced their waist size, regardless of which version of the obesity gene they had. Interestingly, people with the “risk” version of the gene started out heavier but still benefited from the diet. However, the diet didn’t reduce inflammation markers as much as researchers hoped. This suggests that eating plenty of protein might help counteract the effects of genes that make weight gain easier.

The Quick Take

  • What they studied: Whether eating a high-protein, low-calorie diet helps people with different versions of the obesity gene lose weight and reduce inflammation in their body.
  • Who participated: 60 adults aged 18-50 years old who were overweight or obese, divided into three groups of 20 based on their FTO gene type. Participants had no serious health conditions.
  • Key finding: After 4 weeks on the diet, all groups lost weight and reduced waist size (p = 0.02 for weight loss). People with the ‘risk’ gene version lost weight just as effectively as those with other gene versions, suggesting the high-protein diet helped everyone.
  • What it means for you: If you carry genes that make weight gain easier, eating more protein while reducing calories may still help you lose weight. However, this was a short 4-week study, so we need longer research to know if results last. Talk to your doctor before starting any strict diet.

The Research Details

This was a short-term intervention study where researchers gave 60 overweight and obese adults the same diet for 4 weeks. The diet was very strict: only 800 calories per day with about 100 grams of protein (roughly the amount in 14 eggs or 1.5 pounds of chicken). Before the study started, researchers tested each person’s blood to determine which version of the FTO obesity gene they had. There are three possible versions: AA (the ‘risk’ version), TT (the ‘protective’ version), and AT (a mix). Researchers measured weight, waist size, hip size, and took blood samples at the beginning and end to check for inflammation markers.

The study design allowed researchers to see if the diet worked differently depending on which gene version people had. By dividing people into three groups based on genetics, they could compare whether the ‘risk’ gene group responded differently than others. This approach helps answer the question: does your genes determine whether a diet will work for you?

Understanding how genes affect weight loss is important because it explains why some people seem to gain weight more easily than others. The FTO gene is one of the most well-known genes linked to obesity. If we can show that diet can overcome genetic disadvantages, it gives hope to people who feel their genes work against them. This research also helps doctors give more personalized advice based on a person’s genetics.

This study has some strengths and weaknesses. Strengths: it measured actual body changes (weight, waist size) and used genetic testing to divide groups fairly. Weaknesses: the study was very short (only 4 weeks), the diet was extremely strict (800 calories is quite low), and there was no control group eating a normal diet to compare against. The sample size of 60 people is relatively small. The study doesn’t tell us what happens after people stop the diet or whether results would be similar with a less restrictive diet.

What the Results Show

The high-protein, low-calorie diet successfully reduced weight in all three genetic groups. On average, participants lost weight (p = 0.02), reduced their body mass index or BMI (p = 0.03), and decreased their waist circumference (p = 0.02). These are all signs of meaningful weight loss.

Interestingly, people with the ‘risk’ version of the FTO gene (AA group) started the study heavier than others—averaging 95.74 kg compared to the TT group. Despite starting heavier, they still lost weight on the diet, showing that the high-protein approach worked for them too. This is encouraging because it suggests that having the ‘risk’ gene doesn’t mean a diet can’t work for you.

The researchers also looked at how much of the weight difference between groups was explained by genes. They found that the FTO gene explained about 16% of weight differences, 11% of BMI differences, 24% of waist circumference differences, and 14% of waist-to-hip ratio differences. This means genes matter, but they’re not the whole story—other factors like diet, exercise, and lifestyle choices still play major roles.

The study measured inflammation markers in the blood (specifically CML and IL-6) to see if the diet reduced inflammation, which is often elevated in people with obesity. Surprisingly, the diet did not significantly reduce these inflammation markers after 4 weeks, even though weight loss occurred. This was unexpected because researchers thought that losing weight would automatically reduce inflammation. It’s possible that 4 weeks wasn’t long enough to see changes in these markers, or that the very low calorie diet (800 calories) might have affected inflammation in complex ways.

Previous research has shown that high-protein diets can help with weight loss and that the FTO gene affects obesity risk. This study adds to that knowledge by showing that high-protein diets may work well even for people with the ‘risk’ version of the FTO gene. However, other studies have found that very low-calorie diets (like the 800-calorie diet used here) can sometimes increase certain inflammation markers, which aligns with the unexpected finding that inflammation didn’t improve in this study.

Several important limitations should be considered: First, the study only lasted 4 weeks, which is very short. We don’t know if people kept the weight off after the study ended or if results would be similar over months or years. Second, the diet was extremely restrictive at 800 calories per day—most nutrition experts recommend at least 1,200-1,500 calories daily. This makes it hard to know if similar results would happen with a less strict diet that people could follow long-term. Third, there was no comparison group eating a regular diet, so we can’t be sure the weight loss was due to the high protein or just the low calories. Fourth, the study only included 60 people aged 18-50 with no other health conditions, so results might not apply to older adults or people with diabetes or heart disease. Finally, the study didn’t measure how people felt, their energy levels, or whether they could stick to the diet—important real-world factors.

The Bottom Line

Based on this research, eating more protein while reducing calories may help with weight loss, even if you carry genes that increase obesity risk. However, the 800-calorie diet used in this study is too strict for most people to follow safely long-term. A more moderate approach—eating 1,200-1,500 calories with adequate protein (about 25-30% of calories from protein)—might be more sustainable. Before starting any weight loss diet, especially a very low-calorie one, consult your doctor or a registered dietitian. Confidence level: Moderate. This study shows promise but is short-term and uses an extreme diet.

This research is most relevant for adults who are overweight or obese and wondering if their genes make weight loss impossible. It offers hope that diet can work regardless of genetics. However, people with diabetes, heart disease, kidney disease, or other health conditions should not follow an 800-calorie diet without medical supervision. Pregnant or breastfeeding women should avoid very low-calorie diets. Athletes and very active people may need more calories and protein than this study provided.

In this study, people saw weight loss and waist reduction within 4 weeks. However, 4 weeks is very short. Realistically, you should expect to see meaningful changes in weight and measurements within 4-8 weeks of consistent effort, but the diet needs to be sustainable. Most experts recommend aiming for 1-2 pounds of weight loss per week. Very rapid weight loss (like in this 4-week study) is often hard to maintain long-term.

Want to Apply This Research?

  • Track daily protein intake (in grams) and total calories consumed. Set a goal of 100g protein daily and monitor whether you hit this target. Also track waist circumference weekly (measure at the narrowest point) and weight 2-3 times per week. This gives you multiple measures of progress beyond just the scale.
  • Use the app to log meals and identify high-protein foods you enjoy (chicken, fish, eggs, Greek yogurt, beans, nuts). Create a meal plan with 3-4 high-protein breakfast, lunch, and dinner options you can rotate. Set daily reminders to drink water and eat protein at each meal, since protein helps you feel full longer.
  • Set up weekly check-ins to review your protein intake average, calorie totals, and body measurements. Create a chart showing waist circumference and weight trends over 4-8 weeks. If progress stalls after 2-3 weeks, adjust portions or try different high-protein foods rather than cutting calories even lower. Track how you feel (energy, hunger, mood) alongside physical measurements to ensure the diet is sustainable for you.

This research describes a 4-week study using a very low-calorie diet (800 calories daily), which is significantly below standard dietary recommendations. Do not start this diet without consulting your doctor or registered dietitian, especially if you have any health conditions, take medications, are pregnant or breastfeeding, or have a history of eating disorders. This article is for educational purposes only and does not constitute medical advice. Individual results vary based on many factors including overall lifestyle, exercise, sleep, and stress. Genetic testing for the FTO gene is not necessary to benefit from a healthy, high-protein diet, and genes are only one factor affecting weight—diet, exercise, sleep, and stress management are equally important.