5 diet changes supported by research evidence

The Bottom Line

  • Include fish (or fish oil supplements) in your diet and cut down on salt and saturated fat.
  • The structure of a Mediterranean diet plan can help you make healthy changes.
  • Be aware that larger plates and portion sizes can cause you to eat more.
  • Consult a doctor or dietician to develop a diet plan, particularly if you have a medical condition or take medication that can be affected by your diet.

Feeling overwhelmed by all the diet and nutrition advice out there? You’re not alone. Television, newspapers, magazines, radio, the internet... everywhere you turn there are ads and articles telling you what you should and shouldn’t eat. Unfortunately the information is often unproven, contradictory and just downright sketchy. It’s tempting to give up and give in to your sugar/salt/saturated fat cravings and let the chip crumbs fall where they may (usually between the seat cushions).

But it’s a far better idea not to. A nutritious, well-balanced diet is important to health and well-being throughout the lifespan and helps us maintain strength, mobility and a good quality of life as we age. It’s never too late to make better food choices but some people try to do too much at once, which can lead to frustration and failure.

Take five for better health

Why not start with just a few changes, such as the five listed below? They’re simple, sensible and proven to help promote healthy aging based on research evidence from recent systematic reviews. Click the links to read the articles, including details about the research findings.

1. Please pass (up) the salt

You’ve always heard that too much salt is bad for you. Now research confirms the benefits of cutting back: reducing your sodium intake will help lower your blood pressure, which in turn decreases your risk of heart disease. The main culprit is processed foods (1).

2. Nothing fishy about this advice

Another good way to promote heart health is to eat more salmon, mackerel, tuna and other fish high in omega-3 fatty acids. Don’t like fish? Try fish oil supplements. Research shows that people with high blood pressure who took fish oil supplements saw a small drop in their blood pressure readings (2).

3. Cut the (saturated) fat

When it comes to our diet, not all fat is created equal. Saturated fat – common in meat and dairy – is the one we need to be most concerned about. According to research, reducing the saturated fat in our daily diets and replacing some with healthier unsaturated fats – found in plant oils – can lower our risk of heart disease (3).

4. Go Mediterranean

Need the structure of a diet plan to stay on track? There are so many to choose from, ranging from the sensible to the bizarre. The Mediterranean diet is one of the former. It supports the other recommendations by encouraging people to eat more vegetables, fruit, fish, whole grains and unsaturated fats such as olive oil (4-7). A vegetarian diet is another option that emphasizes similar foods and plant-based fats and protein (8).

Diabetic? There is evidence that a Mediterranean diet can also improve your blood sugar, insulin and blood pressure levels as well as help you lose weight (6;7).

5. Take care with your choice of tableware

For people who are overweight or at risk of obesity, reducing portion sizes can help cut down on un-needed calories. Did you know that the size of the plate, package or portion you are offered can influence how much food you eat and drink? Use a smaller plate and say no to ‘super-sized’ portions to help avoid the health risks associated with weight gain (9-11).

Small, steady improvements for long-term success

When you’re ready to make some healthy diet tweaks, the suggestions above are a good place to begin and can help get you on the right track without biting off more than you can chew (which is also another good eating tip). You can then incorporate additional nutrition and lifestyle changes as needed to help you achieve your own personal health goals.

It’s also a good idea to discuss your diet plan with your doctor, particularly if you have a chronic disease or other medical condition that can be affected by your diet.

Happily, there are a lot of foods that are both good tasting and good for you. Bon appétit!

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Author Details


  1. He F, Jiafu L, MacGregor G. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomized trials. BMJ. 2013; 346:1325. doi: 10.1136/bmj.f1325.
  2. Campbell F, Dickinson HO, Critchley JA, et al. A systematic review of fish-oil supplements for the prevention and treatment of hypertension. Eur J Prev Cardiol. 2013; 20:107-120. doi: 10.1177/2047487312437056.
  3. Hooper L, Martin N, Jimoh OF, et al. Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev. 2020; 8:CD011737. doi: 10.1002/14651858.CD011737.pub3.
  4. Karam G, Agarwal A, Sadeghirad B, et al. Comparison of seven popular structured dietary programmes and risk of mortality and major cardiovascular events in patients at increased cardiovascular risk: Systematic review and network meta-analysis. BMJ. 2023; 380:e072003. doi: 10.1136/bmj-2022-072003.
  5. Pant A, Gribbin S, McIntyre D, et al. Primary prevention of cardiovascular disease in women with a Mediterranean diet: systematic review and meta-analysis. Heart. 2023; 109(16):1208-1215. doi: 10.1136/heartjnl-2022-321930.
  6. Huo R, Du T, Xu Y, et al. Effects of Mediterranean-style diet on glycemic control, weight loss and cardiovascular risk factors among type 2 diabetes individuals: A meta-analysis. Eur J Clin Nutr. 2015; 69(11):1200-1208. doi: 10.1038/ejcn.2014.243.
  7. Bonekamp NE, van Damme I, Geleijnse JM, et al. Effect of dietary patterns on cardiovascular risk factors in people with type 2 diabetes. A systematic review and network meta-analysis. Diabetes Res Clin Pract. 2023; 195: 110207. doi: 10.1016/j.diabres.2022.110207.
  8. Huang R, Huang C, Hu F, et al. Vegetarian diets and weight reduction: A meta-analysis of randomized controlled trials. J Gen Intern Med. 2016; 31(1):109-116. doi: 10.1007/s11606-015-3390-7.
  9. Hollands GJ, Shemilt I, Marteau TM, et al. Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco. Cochrane Database Syst Rev. 2015; 9: CD011045. doi: 10.1002/14651858.CD011045.pub2.
  10. Hansen KL, Golubovic S, Eriksen CU, et al. Effectiveness of food environment policies in improving population diets: A review of systematic reviews. Eur J Clin Nutr. 2022; 76(5):637-646. doi: 10.1038/s41430-021-01008-y.
  11. Jia SS, Liu Q, Allman-Farinelli M, et al. The use of portion control plates to promote healthy eating and diet-related outcomes: A scoping review. Nutrients. 2022; 14(4):892. doi: 10.3390/nu14040892.

DISCLAIMER: These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (info@mcmasteroptimalaging.org).

Many of our Blog Posts were written before the COVID-19 pandemic and thus do not necessarily reflect the latest public health recommendations. While the content of new and old blogs identify activities that support optimal aging, it is important to defer to the most current public health recommendations. Some of the activities suggested within these blogs may need to be modified or avoided altogether to comply with changing public health recommendations. To view the latest updates from the Public Health Agency of Canada, please visit their website.