How many times have you read that carbs will make you fat? You are not alone if you have been convinced that carbs are off the menu if you want to achieve and maintain a healthy weight. The good news is that this statement is not as black and white as it appears. A donut does not have the same effect on your body as wholegrains for example.
Wholegrains have several nutrients which support your health. If your goal is to achieve and maintain a healthy weight this food group is not the enemy but in fact may help you to achieve these goals. Studies suggest that wholegrain may promote your health and wellbeing by reducing your risk of chronic diseases like heart disease, certain cancers like bowel cancer and type two diabetes.
Wholegrains are classified by the Australia New Zealand Food Standards Code as ‘“The intact grain or the dehulled, ground, milled, cracked, or flaked grain where the constituents – endosperm, germ, and bran – are present in such proportions that represent the typical ratio of those fractions occurring in the whole cereal, and includes wholemeal.” Wholegrains can include brown, red, or black rice, oats, wholegrain bread, wholegrain pasta, wholegrain couscous, quinoa, teff, corn, barley, sorghum, rye, millet, and triticale.
Previously, there has been limited stronger based study designed like randomized control trials to support that wholegrains may help reduce your risk of developing obesity and help with weight loss. A recently published study used a randomized controlled parallel intervention. This is a stronger form of study compared to previous studies on wholegrains which were often observational studies.
The researchers examined the effects of high fibre rye cereal foods compared to refined wheat foods. The study was conducted for 12 weeks duration. 242 participants followed both a diet of either high fibre rye cereal diet or a diet which included refined wheat for 12 weeks.
During each phase, the participants had support from dietitians and aimed for a five hundred calorie daily deficit to promote weight loss. The amount of rye of wheat products in the diet each day totaled 650 calories per day. This was estimated to be 30–50% of energy intake each day.
30g of dietary fibre was provided each day for the participants following the high fibre rye diet. An adult is recommended to have between 25-38g of dietary fibre each day to support gut health.
Throughout the study period at 0-, 6- and 12-weeks measurements were taken. This included anthropometric measurements, a dual energy x-ray absorptiometry (DXA) scan, and fasting blood sample collection. Before each clinical examination, participants collected a faecal sample and brought it to the clinic.
At the end of the 12 weeks, both groups lost weight and body fat percentage. However, the group which followed a high fibre rye diet lost more weight than the refined wheat group. In addition, CRP, a marker of inflammation was reduced to a greater level in the high fibre rye diet group.
The effects on the gut microbiome were seen in the different diets. Interestingly, the amount of body fat decrease and body fat percentage in the rye group correlated negatively with change in the abundance of the bacteria group called Holdemania. Also, the reduced body fat mass in the participants was positively correlated with an increase in amount of the group UCG-003 for both the refined wheat group and the high dietary fibre rye group. However, there was a larger increase in the amount of UCG-003 in the rye group compared to the refined wheat group.
Take home message: Wholegrains can support you to be your healthiest and may be the missing link to achieving your weight loss goals. Next time you read a comment that you need to remove carbs to achieve your weight loss goals remember that not all carbs are the same and wholegrains deserve a superhero cape more than villain status.
References:
- Food Standards Australia and New Zealand. Final Assessment Report Application A464. Definition of ‘Wholegrain’. 23rd March 2005. https://view.officeapps.live.com/op/view.aspx?src=https%3A%2F%2Fwww.foodstandards.gov.au%2Fsites%2Fdefault%2Ffiles%2Ffood-standards-code%2Fapplications%2FDocuments%2FA464%2520Wholegrain%2520FAR1.doc&wdOrigin=BROWSELINK
- Iversen KN, Dicksved J, Zoki C, Fristedt R, Pelve EA, Langton M, Landberg R. The Effects of High Fiber Rye, Compared to Refined Wheat, on Gut Microbiota Composition, Plasma Short Chain Fatty Acids, and Implications for Weight Loss and Metabolic Risk Factors (the RyeWeight Study). Nutrients. 2022; 14(8):1669. https://doi.org/10.3390/nu14081669
- Pol, K.; Christensen, R.; Bartels, E.M.; Raben, A.; Tetens, I.; Kristensen, M. Whole grain and body weight changes in apparently healthy adults: A systematic review and meta-analysis of randomized controlled studies. Am. J. Clin. Nutr. 2013, 98, 872–884
- Xu, Y.; Wan, Q.; Feng, J.; Du, L.; Li, K.; Zhou, Y. Whole grain diet reduces systemic inflammation: A Meta-Analysis of 9 Randomized Trials. Medicine 2018, 97, e12995.
- Hollænder, P.L.B.; Ross, A.B.; Kristensen, M. Whole-Grain and Blood Lipid Changes in Apparently Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am. J. Clin. Nutr. 2015, 102, 556–572.
